An intolerable fakeness pervaded PMQs. The tone was set by the Prime Minister, who pretended to be cheerful, while looking in unguarded moments tormented.

She decided to get through the session in part by congratulating any MP who ran the London Marathon. By the time she did this for the third or fourth time, her bogus jollity had become unbearable.

It was like seeing someone with a mortal illness pretend everything is fine. At first one admires their courage, but after a while the evasion of the truth becomes another form of cowardice, and renders any communication impossible.

Nobody mentioned Brexit. That is the fatal condition – fatal at least to Theresa May – which is destroying her prime ministership.

She promised she knew how to deal with it, but she didn’t. Occasional rumours of a miracle cure no longer command credibility. She is doomed, but will not admit it.

Jeremy Corbyn drew a portrait of a nation in decline, afflicted by falling life expectancy, hunger and a violent crime epidemic, all caused by Tory austerity.

In other words, he was in election mode, which is understandable, as there are elections tomorrow. But one had the impression he was trying out these lines for a general election, when he will urge voters to throw out the hard-hearted Tories.

From the Tory benches, Tom Tugendhat attacked her for ignoring American and Australian warnings and allowing Huawei to become a “dragon” in our critical infrastructure, while Johnny Mercer protested at the “abhorrent” prosecutions of aged veterans, charged with committing murder almost half a century ago.

It was during Mercer’s attack that I caught a glimpse of the misery which now afflicts the Prime Minister. She too is being prosecuted, indeed persecuted, in a way which to her must seem deeply unfair.

She benefits from no presumption of innocence. Everything that goes wrong is her fault. This bitter predicament cannot be wished away by pretending everything is all right. No wonder the House was half empty by the end of her performance.