Prime Minister Sir Keir Starmer has urged restraint following Israeli strikes targeting Iran’s nuclear programme.
Fears of a full-scale conflict have been stoked by warnings of “severe punishment” from Iran’s Supreme Leader Ayatollah Ali Khamenei and reports of drone launches in response.
A Cobra meeting is expected early this afternoon to discuss the UK response to the emergency situation.
Foreign Secretary David Lammy has also cancelled a planned trip to Washington DC to meet his his counterpart Marco Rubio, although there is no plan for a ministerial statement in the House of Commons.
UK officials said the UK did not play any part in the action overnight but is continuing to monitor the situation.
The prime minister said: “The reports of these strikes are concerning and we urge all parties to step back and reduce tensions urgently.
“Escalation serves no-one in the region. Stability in the Middle East must be the priority and we are engaging partners to de-escalate.
“Now is the time for restraint, calm and a return to diplomacy.”
A Downing Street spokesman said the UK is prepared to take “every diplomatic step” to prevent Iran developing nuclear weapons.
Asked if the UK is involved in nuclear talks with US and Iran, he said: “On Iran’s nuclear programme, it is more advanced than ever, and it is a clear threat to international peace and security.
“We’ve urged Iran to continue engaging with President Trump’s offer of a negotiated solution and we continue to liaise closely with our partners on this.
“We remain committed to finding a diplomatic solution but are prepared to take every diplomatic step to prevent Iran from developing nuclear weapons, including through snapback, if necessary.”
The UN snapback mechanism would lead to the re-imposition of international sanctions against Iran developing nuclear weapons, which had been lifted in 2015.
Conservative leader Kemi Badenoch declined to condemn Israel’s actions, stressing “Iran is an enemy of the UK” that had attempted terrorist acts “on UK soil”.
She added: “If Israel is stopping Iran from getting nuclear weapons they should not be condemned for that.”
Badenoch added the UK should be increasing defence spending as well as energy security.
Posting on X, David Lammy stressed stability in the Middle East was “vital” for global security.
“Further escalation is a serious threat to peace and stability in the region and in no-one’s interest,” he said.
“This is a dangerous moment and I urge all parties to show restraint.”
Rubio also said that Israel acted unilaterally, adding in a post on X, that the US is “not involved in strikes against Iran and our top priority is protecting American forces in the region”.
The attack appeared to be the most significant Iran has faced since its war with Iraq in the 1980s.
Israeli Prime Minister Benjamin Netanyahu said that Israel had “struck at the heart of Iran’s nuclear enrichment programme” and “the heart of Iran’s nuclear weaponisation programme”.
Netanyahu added the “operation will continue for as many days as it takes to remove this threat”.
Iranian state television reported that the leader of the paramilitary Revolutionary Guard Hossein Salami was killed as well as chief of staff of the Iranian armed forces, General Mohammad Bagheri.
Liberal Democrat leader Sir Ed Davey said international leadership is needed from the UK government.
“People across the UK and the world will be fearing the break-out of widespread regional conflict in the Middle East, following Israel’s strikes overnight,” he said.
“The UK must work with allies to contain Iran’s nuclear ambitions through diplomacy, not war.”