A daily stop number system has also been introduced under which, depending on staff available, individual callers beyond a certain number will not have their applications considered on the day they queue up.
The inquiries might seem routine - for a typical foreign businessman or individual it might involve having a passport endorsed with the terms of their stay or to record a work permit extension - but speedy action is often urgently needed to facilitate trips from and returns to the UK.
Julia Onslow-Cole, a partner in Cameron McKenna, which is ranked as the leading business immigration firm by the Legal 500 directory, said her firm's outdoor clerk was now forced to begin queuing from 1am or even earlier outside the Immigration and Nationality Department's Lunar House building in Croydon, south London to ensure urgent matters were dealt with on behalf of clients.
The problem has become so acute that representatives of multinationals such as Toyota and the investment bankers Merrill Lynch and Goldman Sachs have been obliged to camp out in sleeping bags to ensure that the passports of businessmen and women are in order.
The Home Office said yesterday that there had been a large increase in applications over the last 12 months and insisted that the public inquiry office was intended for personal applicants making single applications. But Ms Onslow-Cole, chairman of the International Bar Association Migration and Nationality Committee, said: "This situation is intolerable for business and individuals alike. It is ludicrous to suggest that a senior executive of a large corporation bringing jobs and investment to the UK should personally queue up on the pavement at Lunar House."
Hilary Belchak, secretary of the Immigration Law Practitioners Association and partner in another leading business immigration firm, Simmons & Simmons, said: "We think the present situation is intolerable. We call for urgent talks with the Home Office to sort out a more effective and fair arrangement for all concerned."Reuse content