Rishi Sunak has declined to say he would vote for an emergency budget brought forward by Liz Truss to enact tax cuts, after arguing that it would cause an inflationary spiral and damage the economy. The former chancellor has made increasingly forceful attacks on Truss’s economic policies in recent days, previously signalling that he would find it difficult to serve in a cabinet she led because of a gulf in positions on the country’s finances. Speaking to BBC Radio 4’s Today programme, he said he was “not going to engage” in whether he would vote for a budget put forward by Truss. “Right now, we should be talking about the major challenges that our country faces: creeping inflation, getting support to people who need it,” he said. Any refusal to back a Truss budget if she wins would definitively rule Sunak out of a government job and potentially even put at risk his place in the party. Sunak, who is trailing in the leadership contest, also said he was “very privileged and humbled” that supporters of Margaret Thatcher’s economic policies, including the former chancellor Nigel Lawson, were backing him. Citing Thatcher as one of his biggest influences, he said: “She knew that you have to grip inflation – tax cuts funded by borrowing aren’t a sensible approach, but also this … actually, one thing I admire and respect about her, and I think many other Conservatives do as well, is she was prepared not just to say the easy things that people may have wanted to hear. “She said the things that may have been difficult to hear, but were right for the country and had the courage of her convictions. And that’s the standard that I hold myself to. I don’t want to make promises that I can’t keep. And that’s why I believe my plans are the right ones for our nation.” Throughout the campaign, Truss has focused on her determination to cut taxes in an emergency fiscal event likely to be held in mid-September. She has cast doubt on the need for “handouts” to help people with their energy bills, but softened her stance on that in recent weeks by suggesting the most vulnerable could get help. Sunak has accused her of having the wrong priorities. “When it’s over I’m sure we can look back and reflect,” he said. “But one thing is clear – there is a very clear difference of opinion in this leadership election, there is a difference of opinion in how you grip inflation and whether that’s a priority or not; there’s a difference of opinion about whether you prioritise – in my view – helping vulnerable people with the cost of living rather than giving tax cuts funded by borrowing to very large companies and relatively wealthy people. “Those are big differences, and it’s right that we have a debate about them because they are going to shape the course of our nation over the coming months and years, so I think it’s important these ideas are debated.” He said any measures to alleviate the cost of living had to be affordable and not make inflation worse, because otherwise it would be a “gamble with people’s savings, with their pensions, with mortgage rates”. The result of the leadership contest is due to be announced in 12 days’ time, on 5 September.