March 3 (Reuters) - Britain said on Tuesday it would block study visas for nationals from four countries and halt work visas for Afghans, using what it called an "emergency brake" to curb rising asylum claims from people entering through legal routes.
Immigration remains one of Britain's most politically sensitive issues, and Prime Minister Keir Starmer's government has sought to show it is tightening the system as the populist Reform UK party gains ground in opinion polls.
