Boris Johnson hopes voters want him to be 'responsible', writes Robert Peston

Boris Johnson just took a very big political risk, by NOT making any serious attempt to compete with Labour on bunging cash at public services and the fabric of the UK.

Where Corbyn is pledging £83bn a year of increased spending on students, the elderly, health, schools, public-sector pay and so on by 2023, the Tories offer £3bn.

For Labour’s £80bn plus per year on new housing, pension compensation for women born in the 1950s, nationalisations, greening businesses and multiple other projects, Johnson is committing to £8bn by the end of the next parliament.

To be clear, Johnson’s relative parsimony is not quite what it seems - because the Tories already made their big pledges to increase hospital, police and schools funding before the election.

And his manifesto does include just under £1.6bn a year of new money to train and recruit 50,000 additional nurses and 50m more GP appointments.

Also, Johnson has kept in reserve almost £60bn of firepower for further investment over the next four years - which is either sensible contingency planning or utterly eccentric when Labour is offering humongous bribes to every demographic.

Johnson is making two calculations.

First he assumes a majority of wavering voters will agree with him that Corbyn’s massive plans to spend, borrow and tax are too ambitious and will scare away important investors from the UK, to the extent that ultimately we’ll all be left poorer.

And his second bet is that his pledge to extract the UK from the EU by 31 January, coupled with Corbyn’s new vow of perpetual silence on whether he supports Remain or Leave, will count for more than the responsibility of the Tories since 2010 for the perceived squeeze on the ability of schools and hospitals to meet our needs.

For the avoidance of doubt, Johnson is not offering a small-state Thatcherite vision of the economy.

But it is quite telling that by freezing planned corporation tax rises, he has actually increased from £4.4bn to £5.6bn his cushion over four years for the risk that revenues are less than he expects or spending exceeds plans.

In that sense he is hoping that relative prudence in managing the government’s finances remains a Tory vote winner.

After all the hard years of austerity, his lesser fiscal gamble translates into a bigger political gamble.