The Liberal Democrats have revealed information from a Parliamentary question that suggests that Labour’s immigration legislation is not being taken seriously by some employers.

In the last 18 months there were 3,164 illegal labour penalties given out to companies by the UK Border Agency, mainly to restaurants and takeaways,  and 1,301 remain uncollected with a total of about £6.5 million thought to be unpaid.

These statistics are the latest blow to the Government’s campaign against companies that employ illegal workers.

Last summer it was revealed that the average fine imposed on guilty companies was £5,000, which is only half the maximum penalty, while Baroness Scotland, the Attorney General, faced calls to resign in September after she admitted employing an illegal immigrant as her housekeeper.

The Liberal Democrat Shadow Home Secretary, Chris Huhne , who released the figures called for ministers to tighten fine collection procedures to ensure rogue firms could not ignore the rules.

Chris Huhne said.:

“The Government has belatedly got round to identifying unscrupulous employers who profit from the exploitation of illegal workers,”

“It seems when they do find them there are no guarantees that they can get them to cough up any of these profits.

“We need to clamp down on rogue employers and the only way to do this is to make sure that they pay the fines they are given.”

The Home Office said the Government will vigorously pursue unpaid fines.

Legislation covering illegal workers was tightened in February 2008, with firms facing a sliding scale of penalties based on how diligently they attempted to research their employees’ backgrounds.

A Home Office spokesman said:

 ”We are determined to crack down on illegal workers and those who employ them, and the civil penalty system is one of the ways we are doing that,”

In August the UK Border Agency disclosed that householdnames including the restaurant chains Pizza Hut and Chez Gerard and the oil firm BP were among the firms to have been fined under the new rules.