The UK government will have to sign off on the US use of its Diego Garcia base in any bombing raid on Iran, it has emerged, as ministers gathered to discuss a range of scenarios amid further increasing tensions in the region.
The prime minster, Sir Keir Starmer, chaired an emergency Cobra meeting to discuss the UK’s response to the crisis in the Middle East which could escalate further should the US enter the conflict between Israel and Iran.
After the prime minister landed back in Britain following the G7 summit in Canada, he brought together ministers and senior officials to update the UK’s response beyond urging de-escalation.
But with Donald Trump still not revealing what action he may take, the UK government is working on a series of options dependent on whether the US pursues military action, and if it asks allies for support at any stage.
One key issue for the UK would be whether to give permission for the US to fly B-2 stealth bombers from the Diego Garcia airbase in the Indian Ocean to attack Iran’s nuclear enrichment site, which is between 80 and 90 metres inside a mountain at Fordow.
The decision on whether to grant the US permission to use the base, should it request to do so, would be a political one, and Starmer would be expected to seek the advice of his national security adviser, Jonathan Powell, who was Tony Blair’s No 10 chief of staff at the time of the Iraq war.
However, government insiders suggested it would put the prime minister in a difficult situation, balancing his stated preference for a diplomatic solution with his desire to safeguard the US-UK relationship that he regards as of the utmost importance.
The US president declined to answer reporters’ questions on whether the US was planning to strike Iran or its nuclear facilities. “Nobody knows what I’m going to do,” he said. He added the Iranians had reached out, but he felt “it’s very late to be talking”.
Starmer had said he was confident the US would not join Israel’s bombing campaign despite US military deployments to the region and mixed messages from Trump, but Downing Street was unwilling to repeat Starmer’s comments on Wednesday.
The foreign secretary, David Lammy, has also travelled to Washington for urgent talks with his American counterpart, Marco Rubio.
British officials have repeatedly emphasised that the UK is not expected to participate with its own military in any attack on Iran, unless there were some exceptional circumstances.
The UK has deployed 14 Typhoon jets at Akrotiri to protect its bases and forces and to help regional allies such as Cyprus and Oman if they come under attack.
Britain has not received a formal request from the US to use Diego Garcia in the south Indian Ocean or any of its other airbases to bomb Iran, it is understood, and Trump is thought to want to keep all his options on the table for the moment – including military – to exert maximum pressure on Iran.
The president is described as wanting to seek a deal, though there is a recognition that could change.
Existing agreements mean the US, or any other country, needs British government permission to use any RAF airbase, including Diego Garcia, which was recently the subject of a new 99-year lease agreement with Mauritius that left the UK in full operational control.
In practice, Diego Garcia is mainly used by the US, but the fact that it is ultimately a British base means that Starmer would have to approve its use for an attack on Iran. The US is thought likely to want to request the use of RAF Akrotiri in Cyprus for its air tankers, used to refuel B-2 bombers.
Similar permission would be required if the US wanted to use RAF Fairford in Gloucestershire, where B-2s are based in Europe, though this is considered a less likely option for an attack on Iran’s nuclear sites.
Refusal by the UK would not prevent an attack on the deep-lying nuclear enrichment site at Fordow because it is possible for the B-2 bombers to strike from their home base in Whiteman, Missouri, but it would be interpreted as a lack of British support for the attack.
The deputy prime minister, Angela Rayner, standing in for Starmer at prime minister’s questions, insisted the UK would continue to back a diplomatic route to resolving the conflict.
“The one thing I will say is we agree with President Trump that Iran must never have a nuclear weapon, but we’ve been consistent in urging Iran to engage in the diplomatic process and work with the United States, and we continue to support that diplomatic approach,” she told MPs.
The Foreign Office advised British citizens in Israel to stay put and close to shelter, despite the families of embassy staff leaving Israel on Tuesday night.
Downing Street said the government’s priority was to de-escalate the conflict, while Starmer called allies in the region to urge a diplomatic solution.
A spokesperson said: “The prime minister, the foreign secretary, have spoken with partners and counterparts across the region and beyond, including all our allies, to reiterate the need for de-escalation and a return to diplomacy. Our priority is de-escalation and that is what ministers will continue to push.”
