Boris Johnson is considering a raid on a £80bn fund to fuel an infrastructure blitz in regions that helped deliver his election victory, it has emerged.

Speaking in Tony Blair’s former seat, Sedgefield, which voted in a Tory MP last week, Johnson said his party “will repay your trust” and that voters had “changed the Conservative party for the better”.

His visit came as his team prepares for a Queen’s speech on Thursday in which he will pledge to bring his Brexit deal back to parliament before Christmas. It will also include a promise to enshrine increased NHS spending in law.

However, more radical plans are also being looked at in the wake of the Conservative victory. It is understood that the party considered pledging more in infrastructure spending during the campaign, but ultimately opted to be cautious. However, some insiders now want the plans to be re-examined as a way of fulfilling Johnson’s pledge to new voters in the Midlands and the north to remodel his party. The Conservative manifesto stated that its fiscal rules meant approximately £80bn was available in additional capital spending, not all of which has yet been allocated.

More of the money could be spent on new infrastructure as part of the first budget of Johnson’s new administration. The Conservative manifesto included a series of measures designed to boost towns, including the towns fund and a “cultural capital” programme, as well as road and rail schemes.

This week’s Queen’s speech is expected to see the government pledge the first law ensuring increased NHS spending – another attempt to reassure new Tory voters that their concerns are being heard. The Tories have pledged an extra £33.9bn a year for the health service by 2023-24.

Speaking in Sedgefield, Johnson said that Britain had embarked upon a “wonderful adventure” by handing him a majority and the power to push through Brexit. The north-east constituency was one of a swath across the north and Midlands in Labour’s hitherto impregnable “red wall” to go blue, as the Conservatives stormed to an 80-seat majority in the new House of Commons.

“I can imagine people’s pencils hovering over the ballot paper and wavering before coming down for us and the Conservatives, and I know that people may have been breaking the voting habits of generations to vote for us,” Johnson added.

“Nobody wanted this election in the run-up to Christmas, but what an incredible thing you have done,” he said. “You have changed the political landscape. You have changed the Conservative party for the better, and you’ve changed the future of our country for the better. I want to thank all the people of Sedgefield, of Bishop Auckland, of Stockton South, of Darlington – where my ancestors come from, it turns out – North West Durham, Blyth Valley and Redcar.

“We’re going to recover our national self-confidence, our mojo, our self-belief, and we’re going to do things differently and better as a country.”

In a message to Tory MPs, Johnson also echoed the words of Tony Blair when he became prime minister in 1997, saying: “Remember, we are not the masters, we are the servants now. Our job is to serve the people of this country.”

A No 10 source said: “This election was as much about delivering on the people’s priorities as it was about getting Brexit done – and the prime minister understands that.

“We will show the public, especially Labour voters who trusted us with their vote, that we will deliver on the promises we have made on helping with the cost of living, tackling crime and supporting our NHS. This starts with making sure the NHS has the funding it needs to carry on being the best healthcare service in the world. It is one of the key priorities of the people’s government.”