Boris Johnson is coming under pressure from senior Tory figures to pursue legal reforms that would pave the way for a dramatic boost in public spending in Scotland to weaken support for independence.

The prime minister is being urged to follow through with a blueprint drawn up earlier this year on the orders of his predecessor, Theresa May. The idea is to spend directly in policy areas that are devolved to Scotland — such as education and transport — with “funded by the UK” branding.

Stephen Kerr, the former Tory MP who lost his Stirling seat in the general election, has made the call in evidence to an inquiry into strengthening the Union. The inquiry, which has reported to Johnson, was led by Lord Dunlop,