The British government has suspended all immigration applications from Romania and Bulgaria as it investigates claims that cases have been rushed through to clear backlogs in the system.
Mr Tony Blair's government has been plunged into a bitter row after a senior diplomat in Romania claimed there were seriously lax controls that even allowed migrants to come to Britain with forged papers.
The diplomat - the British consul in Romania, Mr James Cameron - has been suspended from his post. Home Secretary David Blunkett has asked the Foreign Office to send investigators to Bucharest and Sofia.
Opposition Conservatives are calling for the resignation of Immigration Minister Beverley Hughes for presiding over "the collapse of the system". She is refusing to go and so far has the backing of her boss, Mr Blunkett.
"I intend to suspend all applications . . . from Romania and Bulgaria as from this morning until we get to the bottom of this," Mr Blunkett said.
The Conservatives yesterday published an e-mail they had received from Mr Cameron, claiming that migrants were being let into Britain despite having forged papers.
The diplomat also said immigration officials lacked the language skills to spot fakes and described the processing of applicants from Romania and Bulgaria as "organised crime and UK immigration policy at its worst".