RAF Mildenhall is set to close by the end of the current decade, it was announced today.

The decision by the US military has sent shockwaves through the area – but was tempered by a pledge that nearby RAF Lakenheath does have a long-term future and will become home to the USAF’s new fighter plane in 2020.

Mildenhall, which has been a USAF base since 1950, currently has 3,200 personnel and 1,000 civilian jobs.

About half of these civilian jobs are UK nationals – 190 locally-hired staff and about 370 MoD civil servants who will be redeployed.

The run-down of the base is due to take effect in four years time and is part of a Europe-wide reorganisation by the USAF aimed at saving about $500 million a year (£330 million).

However while Mildenhall is closing, RAF Lakenheath is due to become the European base for America’s new F-35 Lightning II fighters in 2020 – securing that base’s long-term future.

The USAF says that the closure of Mildenhall will take about £220 million a year from the local economy – but the development of Lakenheath will bring an extra £54 million into the area, giving a net loss of £176 million.

Defence Secretary Michael Fallon was disappointed that Mildenhall was to close, but was delighted that Britain had secured the new Lightning II squadrons.

He said: “Of course, the US decision to drawdown its presence at RAF Mildenhall is disappointing. However, we recognise that such changes are sometimes necessary.”

It had not been a foregone conclusion that the new planes would come to Lakenheath.

Mr Fallon said: “The US department of defence had to choose a location for the F-35 in the future. They could have chosen Germany or Italy and they have chosen Suffolk, which is great news. The Prime Minister has welcomed it and I have welcomed it.

He said the fact that Lakenheath was near Marham, where the RAF Lightning IIs would be based, was crucial: “To have their European base at Lakenheath is great news.”

Attention is now turning to the future of Mildenhall which will be handed back to the RAF once the USAF leaves.

Mr Fallon made it clear that the British military would have no further use for it – and that it would be up to local business organisations and councils to find a future use for the site.

There are several hundred homes at the site and buildings that could be converted into business uses.

The Greater Anglia and Cambridge and Peterborough Local Enterprise Partnerships are expected to a key role in finding a new use for the site.

It has good links with the rest of the country – the A11 which is nearby has just been improved and there are very good links to the high-tech hub of Cambridge.

The runway at the airbase is one of the best in the country, and there have already been suggestions that it could become a replacement for Cambridge Airport which is on the edge of the city.

West Suffolk MP Matt Hancock, a minister in the business department, is to chair a working group looking at future uses for the site with council and business representatives.

There is already concern in local communities. As well as those who work directly for the bases, many other businesses rely on trade generated from American and base personnel.

Pubs and restaurants in the Mildenhall area, and further afield in Bury St Edmunds, are particularly concerned about the likely impact on their businesses – although the continued presence of Lakenheath should give them some relief.