Epsom’s MP and shadow Home Secretary Chris Grayling has written to the companies contracted to produce ID cards warning them the scheme will be cancelled if the Tories win power.

Mr Grayling told the firms the ID cards programme would not be completed under a future Tory Government, and warned ministers against putting “poison pill” provisions into the contracts that would increase the cost of cancellation.

He said: “We intend to scrap the ID card project as one of our first acts if we are successful at the election.

“I am increasingly concerned the Government is putting contractual arrangements in place that are designed to tie the hands of a future Government, and I want to make the contractors aware we do not intend to complete this work.”

The scheme for ID cards, biometric passports and the national identity register is expected to cost more than £5bn.

The cards are already being given to foreign nationals and will be offered to people living in Manchester later this year. Ministers have said scrapping the cards would cost £40m.

Reports over the weekend said Home Secretary Alan Johnson had instituted a review of the policy but, on Tuesday, it was announced the project remained “on progress”.

A Home Office spokesman said: “It is normal and fully within Government guidelines to include break clauses in contracts of this kind.

“It is a decision for the Government of the day to determine whether to invoke such clauses, but equally it would be wholly inappropriate to do so on the basis of opposition policy.

“The Home Secretary has made clear the Government remains fully committed to bringing forward measures to protect people’s identity that have widespread public support.”