British ministers are threatening to shelve plans to sell the Millennium Dome as one Whitehall source said talks with the Irish-backed Legacy consortium were on the brink of collapse.

The cabinet meets next week to discuss the fate of the ill starred attraction amid concerns that its sale could be put off until after a British general election if a deal is not signed with Legacy next month.

Treasury Holdings, Legacy's Irish backers, have accused the government of trying to change the terms of the £125 million deal.

Whitehall insiders said Legacy had come up with new proposals to build property on land surrounding the Dome since being named preferred bidder in November. As a result, the government is asking for a larger share of potential profits from that land.

Mr John Prescott, deputy prime minister, will meet his ministerial colleagues on Thursday to review progress on the sale. The meeting comes at a critical time in the talks.

Insiders on the government's competition team admitted that, if negotiations with Legacy failed to reach a timely conclusion, ministers would prefer to pull the plug on the sale rather than risk it becoming an embarrassment in the run-up to a spring election.

"If it overruns, the government would go back to the drawing board because it would be getting too near the election," one insider said yesterday.

The government is insisting that disagreements with Legacy, headed by Labour donor Robert Bourne, are all part of a normal negotiating process. However, one Whitehall source said the deal was "teetering" on the brink of collapse.