Some Labour MPs have told ministers that they have been besieged by constituents whose relatives have been refused entry to Britain, in the hope of receiving help.
However, several Labour MPs have told The Independent that the number of refusals has gone up. Some believe British officials abroad are overcompensating for Labour's abolition of the "primary purpose" rule which was designed to stop couples marrying solely for the purpose of settling in Britain.
It has also been suggested that the problem might be the fallout from a major drive, just before the general election, to deal with a backlog of immigration cases. All agree that new MPs' inexperience may have exacerbated the backlog, with letters going to the wrong departments and having to be forwarded.
The Foreign Office minister, Baroness Symons, has been forced to write to all MPs about the crisis. She also plans a fact-finding trip to Islamabad, where a computer failure has been causing delays for months, and to New Delhi.
The unit which deals with MPs' representations on visa refusals had 1,000 new cases in June, compared with the usual average for the month of 550. Last year its staff dealt with 7,572 cases - 631 per month - but they have seen 1,500 this August.
The Foreign Office, which is responsible for visa applications made overseas, says there has been no significant increase in either the number of applications or the proportion of refusals. Its officials believe the backlog has been caused by relatives in this country making new appeals on old cases, in the hope that Labour will be more sympathetic than the Tories.
Baroness Symons told MPs in her letter that she planned to give "careful thought" to a number of problems and to write again spelling out her plans to tackle them in the medium and long term.
She told The Independent: "We are continuing to monitor daily the performance of our correspondence unit and are working urgently to improve matters."
However, some experienced Labour MPs are angry about the way the issue is being handled. One said he had spoken to a minister who had complained he could not cross the Lobby of the House of Commons without being approached by half a dozen concerned MPs.
"I think the central problem is with our entry clearance officers and their training and culture. I hesitate to say there is a racist culture but it is hard to avoid that conclusion," said one MP, who did not want to be named. "It's almost as if they are sifting cases by knocking them back and saying the genuine ones will reapply."Reuse content