Labour has been warned of a looming tax revenue 'shock' after another billionaire quit the UK.Hedge fund tycoon Chris Rokos - who paid an estimated £330million to the Treasury last year making him Britain's third-biggest taxpayer - has become the latest to join the exodus.Ministers played down the hit to the public finances, which is enough to pay the salary of 10,000 newly qualified nurses. The Tories said it would take the annual income tax from around 38,000 people to fill the gap, with the average worker contributing £8,510 a year.But economists suggested that the Government could face the consequences of 'some very big UK taxpayers moving offshore' after the next round of self-assessment returns are filed.Labour has imposed massive tax increases since coming to power in 2024, and Andy Burnham and Chancellor John Healey have refused to rule out more in the Budget next month.Hikes so far have included a crackdown on so-called 'non-doms' and inheritance tax, and adding VAT to private school fees. Fears have been mounting about how the Government will fund costly promises to build more council houses, overhaul social care and boost defence spending. Andy Burnham and Chancellor John Healey have refused to rule out more tax increases in the Budget next month Hedge fund tycoon Chris Rokos - who paid an estimated £330million to the Treasury last year - has become the latest to join the exodus