(Adds union, background, detail)
By Costas Pitas
LONDON, June 6 (Reuters) - Ford will close its engine plant in Bridgend, south Wales, by September 2020, a trade union said on Thursday, putting 1,700 jobs at risk in the latest blow to Britain's car industry.
Ford is making cuts in several markets to turn around loss-making operations and has also repeatedly warned the British government that it needs free trade to be maintained with the European Union after Brexit, the terms of which remain unclear.
The Bridgend plant built around 20 percent of Britain's 2.7 million automotive engines last year.
However, a contract to supply Jaguar Land Rover ends in September 2020, which would have left the plant just building Ford petrol engines for export.
Ford operates two factories in Britain making engines, which are exported for fitting in vehicles in Germany, Turkey, the United States and elsewhere. They could face delays and extra costs if Britain leaves the European Union without securing a deal with the EU.
Union officials were meeting representatives from the U.S. automaker on Thursday.
"Ford's decision to shut its Bridgend engine plant in 2020 is a grotesque act of economic betrayal," said Len McCluskey, head of Unite, Britain's biggest trade union.
"We will resist this closure with all our might, and call upon the governments at the Welsh Assembly and Westminster to join us to save this plant, and to prevent yet another grave injury to UK manufacturing."
Ford did not respond to a request for immediate comment.
Britain's once thriving car sector, rebuilt since the 1980s mainly by foreign carmakers, has been suffered slumps in sales, output and investment since 2017.
Ford said in January a turnaround of its European operations would involve cutting thousands of jobs, possible plant closures and discontinuing loss-making vehicle lines.
Workers have long pushed for Bridgend to produce hybrid technology and electric vehicle components alongside a new third-party manufacturer to fill any surplus space but such investment has not been forthcoming.
Honda, which builds just over 10 percent of Britain's 1.5 million cars, announced this year that it would close its factory, in the biggest blow to the sector in many years. It said the decision was not related to Brexit.
A series of investment decisions are pending, including whether Peugeot parent PSA will keep its Ellesmere Port plant open and if Jaguar Land Rover will make electric cars in Britain. (Reporting by Costas Pitas; editing by Guy Faulconbridge)