It's hard to give a definitive answer to a Q like this, but the BBC now broke the news with enough confidence that both Germany and the US will send main battle tanks to Ukraine, albeit in somewhat limited numbers. So the previous talk about coordination and careful accounting of their numbers (so as not to weaken German defenses etc.) appears justified at least in that perspective. It's also noteworthy that it's something like 3 A.M. in Germany now, so the news was broken by the BBC's US correspondents, but they cite Der Spiegel for the German side, although I've yet to located that article with certainty (it's probably this piece which is paywalled).
US President Joe Biden's administration is expected to announce plans to send dozens of M1 Abrams tanks.
German Chancellor Olaf Scholz has also reportedly decided to send at least 14 Leopard 2 tanks. [...]
Citing anonymous sources, US media outlets are reporting that an announcement regarding Abrams shipments to Ukraine could come as soon as Wednesday.
One unnamed official told the New York Times that between 30 and 50 tanks could be sent.
The timeline of any potential delivery, however, remains unclear. [...]
The news of Mr Scholz's decision was broken by Der Spiegel in Germany, citing government sources, before being seemingly confirmed elsewhere.
There has been no official statement from the German government yet. The chancellor is due to address the German parliament on Wednesday morning.
Previously, after the new German MoD Pistorius ordered an assessment of how many Leopards they have and in what condition they are, they were mostly pushing back against the press pressing them...
German government spokesman Steffen Hebestreit said Monday that it was important for Germany not to take a “reckless” step that might be regretted afterward, adding that a decision would not be rushed.
“These are hard questions of life and death,” he added. “We have to ask what this means for the defense of our own country.”
Pressed on how long a decision on sending tanks might take, Hebestreit said: “I assume that it’s not a question of months now.”
Pistorius (on Fri) also said something like "I've been in this job for only 24 hours".
As I mentioned in a previous answer, earlier in January, there were certainly some voices in the SPD (like their "defense policy spokesman" Wolfgang Hellmich) who were seemingly more opposed (drawing a distinction between main battle tanks as "attack tanks" and IFVs like Marder as more suitable for defense), but those voices/concerns apparently have been overcome in the meantime.
As Germany's top official likes to emphasize coordination with allies on these matter, perhaps one could quote Macron (albeit he is the French president--but he seems to have summarized those more concisely--at a joint conference with Scholz on Sunday) of what the concerns generally were/are, around this decision, in both French and German quarters:
Macron said any joint decision on whether or not to send heavy tanks depended on three criteria –- that it not "escalate" the conflict; that it provide "real and effective support" to Kyiv's forces including in view of how long it would take to train Ukrainians to use them; and that it "not weaken our own defence capabilities".
It's also worth noting here that despite Germany producing over 3,000 Leopard 2's, according to Wikipedia, mostly were apparently exports, with Germany supposedly having only 320 in their own army stocks. So, the question was probably too a good extent "how many can we send?"
And if an earlier Der Spiegel article (from their int'l ed.) is to be believed... Scholz has had to carefully navigate between the more hawkish and dovish elements of his party, and of the German public at large, which itself is supposedly divided on the tanks issue (those polls supposedly exist, although they might not be public--it might make a good separate Q here) and the coordination issue with allies is also seen as a form of risk-sharing in Berlin:
Scholz’s staff is now considering what a future arms package for Ukraine might look like that includes German Leopards – and something qualitatively comparable from the United States. In their view, that’s the only way to avoid having the dispatch of Leopards look like a unilateral action. There are likely two reasons for Berlin’s reluctance to do so. On the one hand, Berlin is seeking to prevent giving Russian President Vladimir Putin an excuse to portray the West as divided.
And on the other, there is concern that Putin might come to regard Germany as being the primary enemy. Specifically, Scholz's people are worried that, no matter who supplies Leopards to Ukraine, Russia will see them as German tanks. Berlin wants other countries to provide tanks as well so that the risk is diversified.
Scholz is without a doubt saddled with a great responsibility. The chancellor pointed that out himself during a closed-door meeting of the SPD’s national party executive on Monday. According to participants, the Social Democrats debated the tank issue for about an hour. Participants say that Scholz repeated his usual arguments: that he doesn’t want to escalate the situation and that Germany should not go it alone. The chancellor also noted the public’s approval of his approach, noting that there is no majority support in German polls for tank deliveries to Ukraine. Scholz also complained that media reporting on the issue has been one-sided.
A Backsliding Chancellor?
The chancellor came across as defiant to meeting participants, but also clear in his course. Scholz’s SPD is still backing the chancellor, but dissatisfaction is growing over his communication. According to participants, several people at the meeting voiced frustration at the chancellor's lack of openness.
Critics of Scholz accuse him of constantly drawing red lines that he eventually crosses anyway. Early in the war, he said Ukraine was to receive no weapons at all, then no heavy weapons and, finally, no tanks. He then proceeded to break one taboo after the other. Was Scholz constantly backsliding? Sources close to the chancellor say the German leader is simply adapting to a dynamic situation and that there is no playbook for the expansion of military aid to Ukraine.
Berlin and Washington have taken identical approaches in the past year: They have carefully prodded in search of Putin’s red line. First anti-tank weapons, then artillery, then anti-aircraft defense and, most recently, infantry fighting vehicles: Military aid has been adapted to developments in the war and increased in doses, not abruptly. And that’s likely how it will continue.
By the end of the week, Defense Minister Pistorius has stressed, the inventory his ministry is taking of Leopard tanks will be available, an audit to determine how many of the tanks are available, what condition they are in and when they could be deployed. The question is no longer whether the tanks will go to Kyiv, but rather when.
As for the internal German public debates, little of that has been reported in the English-language media, but Politico has an article on the rather acrimonious exchanges between politicians of the ruling coalition last week:
The Greens’ co-leader, Omid Nouripour, said Monday it is “necessary” to finally have clarity on the topic, “as quickly as possible.”
“It is unclear to me why infantry fighting vehicles are not escalating, but battle tanks are,” Nouripour said in reference to Scholz’s readiness to supply Ukraine with Marder infantry fighting vehicles, but not the more powerful Leopards.
The liberal Free Democrats’ Marie-Agnes Strack-Zimmermann, chair of the Bundestag’s defense committee, has called Scholz’s reluctance on the tank issue a “catastrophe” and said the German government had “failed.”
Strack-Zimmermann also got into a public argument with the Social Democrats’ parliamentary group leader, Rolf Mützenich, who accused her of “talking us into a military conflict.” The FDP politician responded on Twitter, calling Mützenich “the symbol of all the central failures of German foreign policy.”
[...] The German parliament’s main opposition group, the center-right CDU/CSU bloc, latched onto the spat to launch a renewed push to split Scholz’s ruling coalition.
“The FDP and the Greens must ask themselves whether they are willing to share responsibility for this failure against their own convictions,” the CDU’s Norbert Röttgen, a member of the Bundestag’s foreign affairs committee, told the newspaper Bild.
Thorsten Frei, chief whip of the CDU/CSU parliamentary group, also urged the FDP and the Greens to “finally act consistently,” and added: “The scenes that are playing out right now in the … coalition are reminiscent of divorce proceedings.”
I'm not sure if there have been more extensive public debates between the SPD faction opposing the sending of heavy tanks and the two smaller parties on this issue. I did find one TV debate in which Strack-Zimmermann was debating that with AfD's Alice Weidel (who was opposed, and that was back in September).
On Jan 25, DW published a poll showing the German public being split on sending tanks, so the mention above (of polls) appears justified:
Scholz has maintained that his cautious approach reflects the reluctance in the German population. A poll released last week showed that Germans were fairly evenly split on the issue, with 46% in favor of sending battle tanks to Ukraine, and 43% against.
The survey, conducted by pollster infratest dimap, found that support among SPD voters for sending tanks was slightly more in favor of sending tanks: 49% wanted to send Leopards, with 40% opposed.
The party supporters most strongly in favor of were those of the CDU, of whom 66% thought Germany should send Leopards, closely followed (somewhat surprisingly, given its roots in 1980's pacifist activism) by Green Party supporters, 61% of whom were in favor.
The neoliberal FDP, meanwhile, was exactly evenly split — 48% in favor and 48% against. That in itself was a surprise since one of Scholz's loudest critics in the last few months has been the FDP's Marie-Agnes Strack-Zimmermann, chairperson of the Bundestag's defense committee, who has visited Ukraine several times in the past year.
Supporters of the far-right Alternative for Germany (AfD), meanwhile, remain the most vehemently opposed to tank deliveries: Some 84% opposed the move.
The smallest party in the Bundestag, the socialist Left Party, is also against arms deliveries to Ukraine.
As CNN notes in their coverage of the same poll, opposition in [former] East Germany was highest, at 59%, in correlation with higher support for the AfD in this region.
And this may or may not be a trend, but some days earlier, on Jan 19, another poll seemingly indicated
Of the 2,025 respondents, 43% opposed the delivery [directly by Germany] and only 39% were in favour. Another 16% did not express a position, the survey, conducted for dpa by the polling institute YouGov, showed. [...]
Despite the reticence of the YouGov poll respondents towards having their country export the tanks, most are not opposed to other countries doing so. A total of 47% would be in favour, with 38% against and 16% undecided.
Apparently only the Russian press agency TASS and a Turkish venue republished this one in English, so it might be at one extreme of the polling results for some of these questions. Still, this one is more interesting to your question, as it shows that opposition to sending Leopards that were in other countries inventories was less than for Germany sending their own tanks. Which might explain why the "red lines" were then crossed in this order.
Another interesting point is that answers to such polls seem pretty sensitive to how they are formulated. More generic polls that simply talked of "heavy weapons" had a substantially higher degree of support, e.g. according to an August "DeutschlandTrend survey, 55 percent of German citizens support the supply of heavy weapons to Ukraine, while 37 percent are against it." Germany was already sending PzH 2000 (self-propelled 155mm howitzers, weighting some 55 tons) to Ukraine at that point, IIRC.
Finally, while I could find no poll on this, the apparently long deliberation seemed to actually go well with some voters...
“I thought it was likable that he was wavering”, said the 73-year-old pensioner from the Düsseldorf area, passing by the Russian embassy on Berlin’s Unter den Linden boulevard on a visit to the capital. “I think the decision is right, but it was also right to take time to think it through.”
Her friend said: “My husband always says, we need to remember that we lost the second world war to the Russians. And if Russia has decided to continue that conflict, then Germany must at least not be in charge of wading in.”
[...] Scholz’s restrained approach is not unreflective of attitudes among the German public, especially among the 64-year-old’s age cohort. “I think what Scholz did over the last week was politically very well thought-through”, said Karl-Ludwig, 63, who had stopped outside the Russian embassy to look at a display of candles and photographs showing ruined Ukrainian cities.
“In terms of communication, they made an absolute mess of something they could have sold as a success”, he said. “But it wouldn’t have been good for Germany to be first to deliver battle tanks.”
The same source (The Guardian) claims that opinion polls had indeed shifted somewhat, recently
Opinion polls only two weeks ago had shown a clear majority of Germans opposed to sending battle tanks to Ukraine. Surveys published this week, before Wednesday’s announcement, indicated a shift, with 44% of those surveyed by the broadcaster RTL in favour of sending Leopards to Kyiv and 45% opposed.
