The Government will be urged to scrap plans to close factories employing disabled workers and embrace the spirit of generosity shown during the Olympic Games.
Workers from Remploy factories will hand in to 10 Downing Street a book signed by more than 8,000 people who support their case.
Half of Remploy's 54 factories are to close by the end of the year, 18 will close or be sold next year and the remaining nine face an uncertain future.
The Government says it believes money will be better spent helping disabled workers find jobs in mainstream sectors.
Sally Kosky, national officer of the Unite union, said in a letter to the Prime Minister: "As a fitting and proper gesture for the forthcoming Paralympic Games, we ask you to reconsider your Government's decision to close the 54 Remploy factories at this 11th hour. Already sites are in the process of being closed or sold off.
"If your ministers are unable to do the morally right thing and keep the factories open, they should ensure that those facing a very grim life on the dole should, at least, be given the same redundancy terms that your Government and the previous administration adhered to.
"Remploy workers are currently facing the dole queue with a redundancy cheque that will be at least £5,000 less than that paid in previous Remploy redundancies, and some will receive over £25,000 less. This is plainly unfair.
"Now is the moment to harness the generosity generated by the Olympics and make a stand for a fairer and better Britain."
Phil Davies, national officer of the GMB union, said: "We have strongly criticised the silence of the Work and Pensions Secretary, Iain Duncan Smith, in failing to offer any help to the soon-to-be made redundant 1,700 Remploy workers; unlike the Welsh Government which has pledged £2.4 million for employers who give jobs to Remploy workers when the factories in Wales close."