Visteon workers, including hundreds from Swansea, have been fighting for better pensions since the car parts manufacturer went into administration in 2009.
Today's petition presentation is the latest in a long line of attempts to fight for some of the money workers say they are owed.
About 200 former workers from Visteon in Swansea, who claim they lost out on their pensions, are handing in a petition to Downing Street today. A High Court hearing is due to take place in May involving all former Visteon car parts workers.
Visteon took over Ford's operations in 2000, and workers were transferred into the new organisation. The firm then went into administration in 2009 and employees claim they lost significant amounts of money. Some say as much as 40% of the expected value of their retirement pensions was lost.
Workers say Ford should have given their pensions greater protections, but the company says is was not their responsibility once Visteon was created. Ford has previously said that it views the claim as being without merit, and will defend its position vigorously.