BBC Defence Correspondent Mark Laity reports on the changing shape of Britain's armed forces

It represents another significant "blurring" of the previously strict divisions between the branches of the armed forces in response to new roles, smaller numbers and tighter budgets.

A Joint Helicopter Command has already been formed.

Harrier GR7: Will eventually be replaced

Under the proposals to be implemented next year, the Navy's Fleet Air Arm Sea Harriers and the RAF's Harrier GR7s will operate together and deploy from the same bases.

The two types of aircraft - one a bomber and the other a fighter - have already operated successfully together from the aircraft carrier HMS Invincible during action against Iraq in the Gulf last year.

Defence Secretary George Robertson said the Joint Force 2000 will be based at two stations 15 miles apart - RAF Cottesmore in Rutland and RAF Wittering in Cambridgeshire.

"This is a practical and symbolic step towards the creation of a truly joint force, capable of reaching the world's trouble spots and, when there, acting effectively," he said.

The move will mean 28 Sea Harriers and 589 jobs moving from the Royal Navy's air squadron base in Yeovilton, Somerset.

Distinct identity

But the government has said the transfer of the Royal Navy's helicopter squadron to Yeovilton will mean a "net increase" of 341 jobs for the Devon base.

Some concessions have been made to traditional service divisions, with each service maintaining its own distinct identity.

The merged unit will come under the jurisdiction of the RAF's Strike Command, while its commanding officer will be a Royal Navy admiral.

Crews will also learn to fly each other's aircraft, although they will retain their own service's uniforms. The Harriers will eventually be retired and replaced by a single multi-purpose aircraft.