The Conservative party has contacted the suppliers in the running for identity cards contracts with a cancellation warning letter.
Shadow home secretary, Chris Grayling, has written to the companies involved in the national identity card project warning them an incoming Conservative government will scrap the controversial £5 billion ID cards scheme.
In April, CSC and IBM were awarded the key system contracts totalling £650 million.
This letter is understood to have been sent to them as well as non-IT companies that are in the running for card and passport production deals.
The opposition party also expressed "concern" that the government may be writing "poison pill" elements into the contracts, in order to prevent the contracts from being easy to cancel. These steps could include large penalty payments to suppliers for cancellation.
"We intend to scrap the ID card project as one of our first acts if we are successful at the election," said Grayling.
"I am increasingly concerned that the government is putting in place contractual arrangements that are designed to tie the hands of a future government, and I want to make the contractors absolutely aware that we do not intend to complete this work."
In May, the government announced that it intends for high street retailers to process biometric details, such as fingerprints and photographs, for identity cards.