Rachel Reeves has ruled out increases to income tax or national insurance under a Labour government.
The shadow chancellor made the pledge after saying both she and Labour leader Sir Keir Starmer want taxes on working people to be lower, although she noted she would not put forward “unfunded proposals”.
Speaking to BBC One’s Sunday With Laura Kuenssberg programme, Ms Reeves also said she did not want to make any cuts to public spending but was unable to give cast-iron guarantees and instead pointed to the need to conduct a spending review if she was in the Treasury.
She later declined to put a timeline on when a Labour government would increase defence spending to 2.5% of gross domestic product (GDP), a measure of the size of the economy.
Ms Reeves also said there is “not going to be a return to austerity” under Labour with commitments to boost frontline services a “down payment on the changes that we want to make”.
She said: “But in the end we have to grow the economy, we have to turn around this dire economic performance.”
The shadow chancellor added: “I don’t want to make any cuts to public spending which is why we’ve announced the immediate injection of cash into public services.
“So that money for our NHS, the additional police – 13,000 additional police and community officers – and the 6,500 additional teachers in our schools, they are all fully costed and fully funded promises because unless things are fully costed and fully funded, frankly, you can’t believe they’re going to happen.”
After being pressed repeatedly on her tax plans, Ms Reeves said: “What I want and Keir wants is taxes on working people to be lower and we certainly won’t be increasing income tax or national insurance if we win at the election.”
She added: “We opposed the increases to national insurance when Rishi Sunak put those forward as chancellor.
“We would like taxes on working people to be lower but unlike the Conservatives, who have already racked up £64 billion of unfunded tax cuts in just three days of this campaign, I will never play fast and loose with the public finances, I will never put forward unfunded proposals.”
Asked when Labour would increase defence spending to 2.5% of GDP, Ms Reeves said: “We’re not going to put a timetable on that.
“We’ve committed to do in government a strategic defence review to make sure that we’re getting value for money for all of our spending, including on defence where some of the procurement costs of purchasing new equipment have, frankly, got out of control under this Government.”
Ms Reeves also insisted Labour “will end fire and rehire” after a union criticised the party for excluding an outright ban on the practice in the final version of its workers’ rights package.
The shadow chancellor said she is “sorry that Sharon feels like that” – after Unite general secretary Sharon Graham said the plans now have “more holes than Swiss cheese” – but defended the pledges.
Ms Reeves said: “We will end fire and rehire which has seen companies… sack all their staff and then try and bring them back on worse contracts.
“That is deplorable and we will not allow that to happen.”