Labour MPs including former Prime Minister Gordon Brown have attacked the UK Government's decision not to provide additional funding to save factories employing disabled workers.
Mr Brown, Thomas Docherty and Lindsay Roy said two Remploy factories, in Leven and Cowdenbeath in Fife, are being put under "a sentence of death" by the inflexibility of the Government.
Eight potential buyers have come forward to take over the under-threat factories, with offers dependent on the terms of privatisation.
But the Fife politicians said progress on a buy-out has been hampered by Work and Pensions Secretary Iain Duncan Smith's refusal to extend transitional financial support to prospective bidders.
The Fife MPs have been pressing for more generous aid to secure the factories' financial viability.
It is impossible for the factories to move from losses of £20,000 or more per disabled worker to full financial viability in one year without a higher level of government help.
The Government is offering £3200 per disabled employee in the first year of privatisation, or £6400 overall over three years.
A letter from Mr Duncan Smith to Mr Brown stated that "no additional transitional funding will be available" and that "any additional financial support over and above that already made available will dilute the focus on people building sustainable businesses, at least in the short term".
But in a statement, the MPs said: "The minister's reply is not good enough. We did not ask for long-term endless support or for large sums of money in aid but we know that keeping the staff on at current levels will require more cash to secure viability.
"We will not allow an inflexible letter from the Work and Pensions Secretary to close the door on financial support that could secure the jobs and workload of two factories.
"The Government have not listened to reasoned arguments in a parliamentary debate secured by us last month and set out in a meeting attended by fellow MPs and a Scottish Government minister.
"The 60-year-old factories at Leven and Cowdenbeath are high-quality manufacturing assets earning export revenue but are under a sentence of death if a higher level of financial support is not raised.
"We will continue to press for a more flexible form of financial support. We have been set back but we will not give up. We have eight indications of interest, six of them from private companies and two from social enterprises, and we will press on for a rescue."