The Department for Transport said it was looking at the possibility of upgrading existing trains to enable them to run using electric power provided by overhead lines.

Two media reports on Sunday said the contract could be worth around 120 million pounds ($191 million).

"We anticipate that, if it proceeds, this work would be delivered largely from within the industry's UK operations and will safeguard jobs at the Bombardier works, including their design team, and with the company's supply chain," the DfT said.

"We have asked the industry to lead a short initial study into whether this is technically feasible and whether there would be a good business case which provided value for money."

Canadian trainmaker Bombardier said in July it would cut more than 1,400 jobs at its plant in Derby, central England, after losing out to German group Siemens in a competition to upgrade rolling stock on another railway.

The Unite union had said the vast majority of manufacturing work by the Siemens-led consortium would be done in Germany, and called on the government to act swiftly to save Britain's last train manufacturer.

Unite general secretary Len McCluskey said in a statement on Sunday the union was still calling on the government to reconsider its original decision on the Siemens deal.