Former Liberal Democrat leader Paddy Ashdown has urged ministers to back Britain's sole helicopter manufacturer rather than placing orders abroad.

In a short Lords debate, Lord Ashdown called for the Government to give a commitment to the Yeovil-based Leonardo helicopter division or risk losing export orders and jobs.

Lord Ashdown said that for decades the people of Yeovil and south Somerset had provided the UK and its allies with "world-beating aircraft" used in conflict zones like Afghanistan and Iraq.

He described Leonardo's Yeovil factory as an "irreplaceable national aerospace asset" but warned about the security of its future, insisting the Government had made "no clear commitment" that they wished to "sustain this unique sovereign ability to design, engineer and manufacture our own rotary aircraft".

The former MP for Yeovil and ex-Royal Marines officer said doubts about the Government's intentions began when the Ministry of Defence (MoD) abandoned the coalition policy of insisting that an order for Apache aircraft must be subject to proper competitive tendering processes and decided instead to buy "off the shelf" from the US.

"Since then, it pains me to say that every procurement action of the Government has reinforced the suspicion that the MoD prefers to buy new aircraft from abroad than to make them ourselves - even if the consequence is that a vital national asset is lost and the Yeovil site degenerates into simply a repair and maintenance facility."

Lord Ashdown said Yeovil-built aircraft had been sold to over 20 countries and was one of the nation's major exporters but customers now questioned that, if the British Government would not buy helicopters made in Britain, why should they. "This is damaging export prospects," he said.

While the shopfloor at Leonardo's currently had plenty of work it was short of the engineering work needed now to prepare for and build the new aircraft of the future, he said.

"What we need is a commitment from the Government that it prefers to buy the next range of aircraft from UK production, rather than from abroad," he told peers.

"I cannot believe that this Government wishes to preside over the disappearance of a key national capability and prefers to make our armed forces dependent on foreign skills when we have such an abundance of our own."

He warned it was not just Yeovil that stood to suffer but thousands of jobs in suppliers were also at risk.

Responding, Business Minister Lord Henley said the Government had spent "considerable sums of money" investing in the UK's military helicopter capabilities, with plans over the next decade to spend more than £10 billion.

He said: "Much of that investment has obviously been focused on Leonardo with more than £1 billion spent on the development and manufacture of 62 Wildcat helicopters, some £800 million spent on delivering 30 Merlin Mk 2 (helicopters) into service and around £330 million developing the Merlin Mk 4 upgrades across a 25 (strong) aircraft fleet."

"That investment is vital in ensuring that we have the helicopter capability that we need in the world of defence for decades to come."

The Government was also supporting Leonardo's diversification into providing civil aircraft, he said.

But the minister added: "Budgetary pressures mean that we are unlikely to be able to maintain national industrial capability in every single area of our defence requirements.

"The Government will continue maintaining industrial capability where that is in the national interest, but in general it will continue to operate a policy of competition to ensure best value for money, best capability and innovation."