Liz Truss’s plans to cut taxes immediately if she becomes prime minister are “immoral”, Rishi Sunak has said.
In a major ramping up of his attacks on his Tory leadership rival, the former chancellor said the move would require the government to borrow “tens and tens and tens of billions of pounds”, which would have to be repaid by future generations.
He also said he was the “underdog” in the contest and said the “forces that be” want Truss to win.
Sunak made his comments while addressing supporters in Grantham, the birthplace of Margaret Thatcher.
Truss has pledged to reverse the rise in national insurance payments and halt the planned increase in corporation tax - policies introduced by Sunak when he was chancellor.
She has insisted that the £30bn cost of the policies can he paid for from the fiscal “headroom” in the economy.
But Sunak said: “I do believe that it is the wrong approach for the government at this moment to be borrowing an extra tens and tens and tens of billions of pounds at a time when inflation is rising to almost double digits and interest rates are already on the rise.”
He added: “Not only do I think it’s the wrong thing for the economy, I do also believe that it’s immoral because there is nothing noble or good about wracking up bills on the country’s credit card that we then pass on to our children and grandchildren.”
Suggesting that Truss was misleading voters, the former chancellor said: “We can cut more taxes, but only if we defeat the enemy of inflation and that can only happen if we are honest about the ravages it causes.
“We must see the danger in front of us and act - not pretend like it isn’t happening or, more dreadful still, make the situation worse, putting people’s homes and savings at risk.
“I will deliver a lower tax economy, I will deliver tax cuts, but tax cuts you can believe in. I will make that happen.”
The most recent opinion poll of Tory party members - who will decide who succeeds Boris Johnson - suggested Truss is 24 points ahead of her rival.
Sunak said: “Be in no doubt, I am the underdog. The forces that be want this to be a coronation for the other candidate.”
Responding to his comments, a spokesperson for Truss said: “Liz‘s plans for tax cuts will reward people for their hard work and effort, allowing them to keep more of their hard-earned money.
“You cannot tax your way to growth. We have the highest tax burden since the 1940s and as prime minister Liz will take immediate action to prioritise growth and cut taxes.
“We can’t continue with a business-as-usual approach on the economy that is failing to deliver for the British people.”
Chief secretary to the Treasury Simon Clarke, who used to work under Sunak when he was chancellor, also hit out at his former boss, accusing him on Twitter of engaging in “project fear”.