Keir Starmer's Labour Party, which leads in the opinion polls and which published its manifesto on Thursday, is targeting Britain's wealthiest people to support a public spending programme focused on schools, welfare, energy reform and the National Health Service.
Around 70,000 people who live in Britain but pay little or no UK tax on the money they earn overseas were already facing higher bills after the incumbent Conservative government said in March it would phase out this «non-dom» status over time.
But in proposals published in April, Labour said it would move faster to scrap relief on foreign-earned income and expand Britain's inheritance tax regime to include foreign assets held in trusts designed to mitigate such levies.
Critics say the proposed changes could do Britain's lukewarm economy more harm than good, making the country a less attractive place for the world's wealthy to live and invest in, reducing overall tax revenues rather than growing them.
The Labour Party did not immediately respond to a request for comment.
Economists say overall tax levels are likely to approach an all-time high whoever wins the election, despite promises by both main parties not to increase major tax rates.
Labour has said it will not raise income tax or National Insurance social security contributions on working people. But it has pledged to narrow the gap between UK tax owed and tax collected, which widened by 5 billion pounds to 36 billion pounds ($46