As Jeremy Corbyn delivered his second question at today's PMQs he appeared to be on a path to victory. In citing the IFS, he said, Theresa May was being a "little bit selective". The think-tank had described the prospects for workers over the next six years as "dreadful". Corbyn continued: "Isn’t it fair to say that those just getting by are suffering all the pain for no gain?”

His question was punchy and well-scripted. But there was a catch. As May immediately noted, Corbyn had mistaken the IMF (whose flattering forecast she had quoted) for the IFS. "Given that he can't differentiate ... It's probably a good job he's sitting there and I'm standing here," the PM ruthlessly surmised. At that moment, Corbyn lost what momentum he possessed.

After the Labour leader chided May for the reduced increase in the minimum wage, she replied:"The one thing we know is that the policy that would not deliver a strong economy is Labour's policy to increase borrowing by £500bn". The party's pledge is in fact to borrow that amount over a decade, with £250bn drawn from the private sector. But May, citing former shadow chancellor Chris Leslie, delivered an easy attack line: "Labour's policy would lead to double income tax, double council tax and double national insurance".

Intriguingly, however, when Corbyn raised the social care crisis, May conceded that the system was "under pressure" and that "we recognise that". When she was rebuked for not providing "a penny extra" in the Autumn Statement, she reminded Corbyn that the Tories were spending more than Labour promised at the last election. "The shadow chancellor - lately of Strictly fame - said local authorities would get not a penny more," she contemptuously remarked of Ed Balls. "The Conservatives putting money into the NHS and social care - Labour would deny it!" To prove that only Nixon can go to China, the Tories did indeed pledge to spend more than Labour at the last election.

Asked by Tory MP Peter Bone about Donald Tusk's refusal to guarantee UK citizens the right to remain in the EU (though in a Corbyn-esque muddle, he claimed Jean-Claude Juncker had done so), May claimed vindication for her refusal to make a reciprocal offer. "It was absolutely right for us not to do what the Labour Party wanted us to do which is to give away the guarantee for rights of EU citizens here in the UK because, as we've seen, that would have left UK citizens in Europe high and dry."

But on Brexit, May remained as opaque as ever. "How on earth can she expect MPs to vote to trigger Article 50 when she refuses to give any clarity?" asked Caroline Lucas (one of those who has vowed to block Brexit). May, as is now traditional, assured her: "We are ambitious in getting the best possible deal".