Boeing was last year handed a $2.9 billion contract to assemble 50 of the next generation of Apache helicopters

Sir Vince Cable has stepped into the row over government links with Boeing to demand that ministers stop handing Americans firms giant multibillion pound contracts for helicopters and instead build them in Britain.

With Boeing under the spotlight for launching a trade battle with Bombardier over the C-Series aircraft, threatening thousands of jobs in Northern Ireland and the wider UK supply chain, the Liberal Democrat leader and former business secretary in the 2010-15 coalition said ministers needed to reappraise their military helicopter procurement.

Boeing was last year handed a $2.9 billion contract to assemble 50 of the next generation of Apache helicopters.

The deal meant that assembly work was taken away from the Westland helicopter factory in Yeovil owned by the European group Leonardo, with