Exclusive: Watchdog may conclude that emigration of wealthy individuals could actually cost Treasury revenue

Keir Starmer’s promised tax crackdown on non-doms could yield no extra funds for the Treasury, leaving a £1bn hole in the government’s planned spending for schools and hospitals.

Labour planned to use the money raised from wealthy individuals who are registered overseas for tax purposes to invest in ailing public services.

But the Guardian understands that Treasury officials fear estimates due to be released by the government’s spending watchdog may suggest the policy will fail to raise any money because of the impact of the super-rich non-domiciles leaving the UK.