Wealthy investors from countries such as Russia who want to settle in Britain face stricter rules on so-called golden visas under a new regime to be announced on Thursday, a crackdown spurred by the Skripal nerve agent attack.

However, transparency campaigners have attacked the shake-up to the visa scheme, which has seen rich overseas investors such as billionaire Roman Abramovich set up home in the UK, as not going far enough.

In an attempted crackdown on money laundering, new Home Office rules that take effect in April will require visa applicants to prove they have had control of more than ￡2m for at least two years, rather than 90 days. The investments will also need to be made in UK businesses, while investing in gilts will be excluded, in an attempt to increase the benefit to the British economy.