Workers at the Chesterfield branch of Remploy are taking part in 5 days of industrial action.
They are upset at plans that could result in 55 people losing their jobs at the struggling firm.
Union bosses say new owners of the factories have been given permission by the department for work and pensions to not offer new workers a pension.
They're also concerned that the 3 potential buyers might sack people based on their individual disability.
If an agreement isn't reached the workers say the strikes could continue indefinitely.
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