Britain placed its armed forces on standby on Thursday after Iran's Islamic Revolutionary Guard Corps warned that UK military installations used by American forces are legitimate targets. The IRGC said US bombing missions had launched from RAF Fairford on 21 July, two days before American forces carried out a 12th consecutive night of strikes against Iran.
New Prime Minister Andy Burnham extended the policy allowing US use of British bases, a move Iranian Deputy Foreign Minister Kazem Gharibabadi said would place host governments in the ranks of aggressors. The UK government withdrew remaining diplomatic staff from Tehran citing the deteriorating security situation.
The conflict, which began with US-Israeli strikes on Iran on 28 February, has escalated in recent days. The latest US airstrikes targeted military sites including maritime capabilities and missile storage facilities. US President Donald Trump has criticised Britain for insufficient support while warning that Iran would face retaliation for any attacks on shipping in the Strait of Hormuz.