Labour has pledged to ban the non-domicile tax status which was enjoyed by Rishi Sunak’s wife.
Multi-millionaire Akshata Murty gave up the perk - which allowed her to avoid paying UK taxes on her international income - following a huge public backlash.
She has since announced that she will pay UK taxes on all of her income, although she will retain her non-dom status.
Shadow chancellor Rachel Reeves said “it simply isn’t right that those at the top can benefit” while ordinary people are facing rises in their own tax bills.
In a further sign of the political damage done to the chancellor, a new poll of grassroots Tories for the ConservativeHome website showed he is now the least popular member of the cabinet.
Labour said that if they win the next election, those from abroad who choose to base themselves in the UK will pay tax to the Treasury on all of their income.
Reeves said: “As the Tories raise taxes on working people, it simply isn’t right that those at the top can benefit from a outdated non-dom tax perks.
“With Labour, people who make the UK their home will contribute to this country by paying tax on their global income.
“The prime minister and chancellor have spent the last few weeks preoccupied with saving their own skins, and have done nothing to tackle the spiralling cost of living.
“Even worse, they’ve made it harder for working people to make ends meet by hiking national insurance.
“Labour is on your side. We will tax fairly, spend wisely and grow the economy.”
Sunak - once heavily tipped to succeed Boris Johnson as prime minister has accused his political opponents of trying to “smear” him by attacking his wife.
He told The Sun newspaper that Murty was entitled to use the so-called “non-dom” arrangement as she is an Indian citizen and plans to move back to her home country to care for her parents.
The fashion-designer daughter of a billionaire married the chancellor in 2009 before he became an MP.
She hasn’t broken any rules. She’s followed the letter of the law,” Sunak told the paper.
The chancellor said his partner “pays full UK tax on every penny that she earns here in the same way that she pays full international tax on every penny that she earns internationally”.