David Lidington is a master of the necessary pieties. He was standing in for Theresa May, who was attending Lyra McKee’s funeral, and he adopted a tone of impregnable bipartisanship while ranging across terrorism in Ulster, terrorism in Sri Lanka, the need for Christians and Muslims to show mutual respect, and a number of other solemn topics.

Would Emily Thornberry, standing in for Jeremy Corbyn, realise that she too must be pious? For she sees her encounters with Lidington as a chance to show-case her comic talents, as if anxious to persuade her colleagues that Labour needs a stand-up comedian as its next leader.

We were spared the jokes, for as even Thornberry realised, “sadly this really isn’t a week for laughter”. That was something, but left her with the awkward task of switching from the murder of McKee, “whose funeral the Prime Minister is right to attend”, to questions about which the Opposition ought to attack the Government.

With a grinding of gears, Thornberry went in via customs arrangements for the Northern Ireland border to the Withdrawal Agreement.

Lidington, full of high sentence and a bit obtuse, urged her honourable and right honourable friends to vote for the Withdrawal Agreement.

Thornberry: “We’ve heard it all before, let’s face it.” She switched to the state visit by Donald Trump, and suggested that at the state banquet, he should be put between Greta Thunberg, the young Swedish environmental campaigner, and David Attenborough.

We seemed to be getting dangerously near to a Thornberry joke. This may, indeed, have been one. It was hard to tell.

Lidington said that only two years ago, Thornberry had declared, “We should welcome the American President.” He wondered whether she has changed her opinion of Trump, or “something has changed about her own leadership ambitions”.

For a moment a ray of sunshine pierced the thick cloud of righteousness. Thornberry retorted that only one side of the House is having a leadership contest at the moment.

But almost at once, the cloud descended again. Kirsty Blackman, standing in for Ian Blackford of the SNP, asked about climate change.

Lidington emitted clouds of dense smoke. Britain is decarbonising faster than any other country in the G20. Rebecca Pow (Con, Taunton Deane) wants us to achieve “net zero emissions ahead of 2020”, which sounded rather ambitious, but she corrected this to 2050, which one fears would be too late to satisfy either Thunberg or Attenborough.

David Tredinnick (Con, Bosworth) asked in an exasperated tone whether we will leave the European Union by 22nd May. Lidington said he “shares that sense of exasperation”.

He did not, however, share anything else. He gave the impression that the Government is utterly becalmed. His marvellous but deeply tedious professionalism was employed to avoid telling us anything we did not already know.

If anything is being done behind the scenes to break the Brexit logjam, Lidington offered no hint of it.