Camden Council could be forced to repay millions of pounds worth of parking fines following accusations that around 20 parking wardens have been patrolling the borough illegally for years.

A tradesman is challenging the legality of hundreds of parking tickets after it emerged that many long-serving wardens fled the service after an immigration check on September 15.

Richard Chaumeton’s construction firm has accumulated up to �91,000 of parking fines, but the Kentish Town builder is taking the council to task over what he claims could be illegal tickets.

Mr Chaumeton, also of London Motorists’ Action Group (LMAG), said: “All those tickets that have been issued are illegal and they should not be valid because they have been handed out by illegal immigrants.

“How can it be lawful for illegal immigrants, who work indirectly for the council, to hand out parking tickets?”

If he is successful, the council could be forced to repay millions of pounds to other drivers who might also have been illegally fined.

It would be yet another blow to Camden’s parking service, which earlier this year was ruled to have amassed �10million in illegal fines from 2009.

Cllr Chris Knight said: “The implications are enormous. If these guys issue up to six tickets or more a day that’s roughly �1.5million worth of tickets a year.”

Parking wardens are employed to the council parking service by private company NSL, which strongly denies the allegations.

A spokesman for the company also rebuffed any suggestion that the legality of tickets is affected by a warden’s immigration status.

The spokesman said: “We were fully staffed on the day in question, and have found no-one working for us who does not have the right to work in the UK. NSL takes its responsibilities as an employer very seriously.”

Mr Chaumeton, who has offices in Grafton Road, alleges that around 20 parking wardens – some who have worked in the borough for seven years – failed to turn up for work last month after being warned of an immigration check.

He claims the missing staff are still on NSL’s books and are receiving holiday and sick pay despite failing to show up for work for more than a month.

A Camden Council spokesman said: “NSL have assured us that their employment practices are robust and that the claims being made are without any foundation.”