When Keir Starmer appeared on BBC Radio 5 Live on Friday morning, he appeared to let the cat out the bag. The Labour leader suggested he would scrap the pension lump sum allowance if he wins next week: “We’re not going to renew it.” Tory politicians couldn’t believe their luck – finally some ammunition for their claim that Labour was not straight in its manifesto over their tax and spend plans.

Only, Labour aides quickly intervened to explain it was simply “an old-fashioned mistake” and Starmer had misspoken. Part of the reason it was seized on is that Starmer (along with Sunak) is already accused by the Institute for Fiscal Studies of a “conspiracy of silence” where both parties are not being upfront with the public about the difficult decisions on the economy. Clearly this is more of a pressing matter for the man who all pollsters expect to be in 10 Downing Street by this time next week.

But increasingly the talk in Labour circles isn’t just about what Starmer might do on tax if the sums don’t add up. Instead, it’s over what Starmer might be temped to do if he does – as the current polls suggest – win a big majority . Labour’s election manifesto was a purposefully cautious document, on the grounds that they did not want to frighten the horses or risk setting targets they will miss.

It means, for instance, that a Starmer government promises a 0.3 per cent increase in teaching numbers per year – roughly a third of a teacher per school. Big talk.