Was it traditional for MPs to fully recline on a House of Commons bench?

Question

At 1:09 of this Sep 18 2019 the Telegraph interview, Jacob Rees-Mogg proclaims

JRM: It's very traditional to sit like that in the House of Commons, it has to be said.

Christopher Hope, Interviewer & Telegraph's Asst Editor: But is it OK on the front bench?

JRM: Do you know, in hindsight, I think not. And sitting comfortably distracted from the importance of what was going on. I do accept it was a mistake.

Other MPs seem to disagree.

“Now, there’s been a lot of talk about democracy tonight and the Leader of the House, who – I have to say – with his body language throughout this evening has been so contemptuous of this house and of the people,” said the Green party MP, Caroline Lucas, as other MPs shouted at him to sit up.

She added, for the benefit of parliament’s written record, that Rees-Mogg had been “spread across three seats, lying out as if that was something very boring to listen to tonight”.

The Labour MP, Anna Turley, called Rees-Mogg’s slouching the “physical embodiment of arrogance, entitlement, disrespect and contempt for our parliament”.

'Sit up!' – Jacob Rees-Mogg under fire for slouching in Commons | Politics | The Guardian

Answer 1

Probably false

Certainly the benches do permit a greater degree of slouching (for example, note the MP to Rees-Mogg's left), though I certainly don't recall seeing anyone sit fully reclined like that.

As mentioned here in a comment, some believed he could be trying to hear better as the speakers are at the back of the bench.

However, in an encounter with reporter Joe Pike, Rees-Mogg says that was not his intention.

JRM: It’s typically trivial of social media.

Me: Were you lying back, trying to hear?

JRM: Sitting comfortably. There’s nothing in the rules about sitting comfortably.

Twitter

Were it to be common, he or his supporters/allies would have defended him with such a claim; note in your quote he abandons this argument very quickly.

MSN UK labels his response as a jest:

He did point out that historically ministers rested their feet on the table and joked that he was “restoring an ancient tradition”

MSN UK

It would seem there is nothing traditional about it; it's a man who at worst is displaying contempt for the politics and at best is just being comfortable.