The move was branded "cruel, callous and calculated", by the country's largest union, Unite.
In July, ministers said 27 Remploy factories would close, arguing the budget for disabled employment services could be spent more effectively.
Some 34 factories have ceased operations since then.
The sites are in the process of closing, but the future of a further 18 factories remained unclear.
Unite general secretary, Len McCluskey, said: "The timing is callous so close to Christmas when ministers had previously said the funding for those sites, due to close or be sold off in 2013, was secure until August and September next year.
"It is a cruel decision, given that of those sacked in the first round of closures, only about 50 have found new jobs in the past three months.
"We call on ministers to stop the closure programme immediately until there is a review of the shambles of selling off Remploy sites to commercial interests, and we can see evidence of the much heralded £8 million 'help and support package' for those disabled workers already sacked.
A Department for Work and Pensions (DWP) spokesman said: "From today, Remploy will invite expressions of interest to take over the running of the remaining factories.
"Our priority throughout this process is to safeguard jobs, which is why we are offering a wage subsidy of up to £6,400 per disabled employee to encourage interested parties to come forward.
"We have also been clear from the start that we have protected the £320 million budget for disability employment services, but we are following the advice of disability expert Liz Sayce to use the money more effectively to get more disabled people into mainstream jobs – the same as everyone else."
Shadow work and pensions secretary Liam Byrne called the move a "shameful act from a contemptuous government".
He said: "Iain Duncan Smith is the minister who said that Remploy workers did nothing better than sit around drinking cups of coffee.
"Now, in a final act of contempt, he has sacked almost all of them, despite knowing that 90% of those who lost their jobs in the last closures are still out of work."
