The United States has to ask permission from the Government to deploy military aircraft to British bases for operations, and it is understood that this has recently been granted.

The B52s will be armed with a number of different precision-guided bombs, including the new Joint Direct Attack Munition, which was used extensively in bombing missions over Afghanistan.

RAF Fairford is a Nato-designated standby base which can be reactivated for operational missions at short notice.

The B52s arriving at RAF Fairford are normally located at the Barksdale US Air Force base in Louisiana. They are expected to be based at Diego Garcia in the Indian Ocean as well as at Fairford.

RAF Fairford is one of only three bases outside the US which can also take B2 Stealth bombers. The other two are Diego Garcia and Guam.

Although it is likely that the Pentagon will want to base America’s most advanced strategic bomber at Fairford for a war with Iraq, no request has yet been made to send B2s there.