Labour has been warned that a wave of wealthy individuals leaving Britain could deliver a "shock" to public finances early next year, after hedge fund billionaire Chris Rokos became the latest high-profile departure. Rokos, who reportedly paid around £330 million in tax last year, is relocating to Greece, which now offers a flat annual tax of €100,000 on overseas income for qualifying foreign residents. Economists warn that such high-net-worth exits are not yet reflected in official tax data, meaning the true fiscal impact may only become clear when self-assessment returns are filed in January and February. The episode adds to pressure on the Government as it weighs further tax rises in next month's Budget.

Analyst Simon French of Panmure Liberum said February could bring a shock to fiscal headroom if self-assessment returns come in weaker than forecast due to wealthy taxpayers moving offshore. Ministers played down the significance, noting Rokos's tax bill was roughly equivalent to the salaries of 10,000 newly qualified nurses, against an average individual income tax liability of just £8,510. Labour has raised taxes substantially since taking office in 2024, including changes to non-dom status, inheritance tax and VAT on private school fees, while government borrowing has hit a 28-year high. Rokos, 55, an Eton and Oxford-educated former state school pupil, donated £190 million to Cambridge University this year and owns Tottenham House, a Grade I-listed mansion in Wiltshire.