Some 200 Bombardier workers and supporters travelled from Derby to London on Wednesday of last week.
The workers are members of the Unite union.
They lobbied MPs at the House of Commons to demand that they take action to save their jobs.
Bombardier, Britain’s only remaining train manufacturer, is making 1,400 of its 3,000 workforce redundant.
This follows a government decision to award the Thameslink train-building contract to Siemens.