A rail union is considering legal action to save 1,400 jobs axed by Bombardier.
Bombardier is being forced to cut jobs after losing out to German group Siemens on a £1.4 billion contract to build 1,200 new carriages for the Thameslink route between Bedford and Brighton.
The Rail, Maritime and Transport union is taking legal advice over a potential challenge on the grounds that the tendering process for the contract was "loaded" against the UK workforce.
"The failure to factor in the wider economic impact in East Midlands makes a total mockery of the government's core claim that Siemens represented best value for the British taxpayer," said RMT leader Bob Crow.
"If that was the grounds for killing off Bombardier then clearly it was based on a total lie and that may be grounds for a challenge."
Canadian-owned Bombardier has announced that after the failure to win the Thameslink contract and with other contracts coming to an end, 446 permanent jobs and 983 temporary contract staff would be cut.
The RMT will challenge the government over the Bombardier jobs during a meeting with Transport Secretary Philip Hammond this week and is pressing ahead with a protest in Derby on July 23.
Thousands of jobs are at stake in the East Midlands because of the cuts at Bombardier, it has warned.