Sir Keir Starmer has disclosed that the UK has permitted the US to utilise British bases for targeting missile sites and silos in Iran for a "specific and limited defensive purpose".

In a video statement posted on social media on Sunday evening, the Prime Minister clarified the UK was not participating in offensive strikes against Tehran.

Here is Sir Keir's statement in full:.

"Yesterday, I spoke to you about the situation in the Gulf and explained that the UK was not involved in the strikes on Iran. That remains the case.

"Over the last two days Iran has launched sustained attacks across the region at countries who did not attack them.

"They have hit airports and hotels where British citizens are staying. This is clearly a dangerous situation".

"We have at least 200,000 British citizens in the region – residents, families on holiday, and those in transit.

"I ask all our people in the region to please register your presence and follow Foreign Office travel advice.

"I know this is a deeply worrying time. And we will continue to do all we can to support you.

"Our Armed Forces, who are located across the region, are also being put at risk by Iran's actions.

"Yesterday Iran hit a military base in Bahrain, narrowly missing British personnel.

"The death of the Supreme Leader will not stop Iran from launching these strikes. Their approach is becoming even more reckless – and more dangerous to civilians.

"Our decision that the UK would not be involved with the strikes on Iran was deliberate, not least because we believe that the best way forward for the region and the world is a negotiated settlement, one in which Iran agrees to give up any aspirations to develop a nuclear weapon.

"But Iran is striking British interests nonetheless and putting British people at huge risk, along with our allies across the region. This is the situation we face today.

"Our partners in the Gulf have asked us to do more to defend them and it's my duty to protect British lives.

"We have British jets in the air as part of coordinated defensive operations which have already successfully intercepted Iranian strikes.

"But the only way to stop the threat is to destroy the missiles at source – in their storage depots or the launchers which are used to fire the missiles.

"The US has requested permission to use British bases for that specific and limited defensive purpose.

"We have taken the decision to accept this request to prevent Iran firing missiles across the region, killing innocent civilians, putting British lives at risk and hitting countries that have not been involved.

"The basis of our decision is the collective self-defence of longstanding friends and allies, and protecting British lives.

"This is in line with international law and we are publishing a summary of our legal advice.

"We are not joining these strikes but will continue with our defensive actions in the region.

"And we will also bring experts from Ukraine together with our own counter drone expertise to help our Gulf partners shoot down Iranian drones attacking them.

"I want to be very clear: We all remember the mistakes of Iraq. And we have learned those lessons.

"We were not involved in the initial strikes on Iran. And we will not join offensive action now.

"But Iran is pursuing a scorched earth strategy. So we are supporting the collective self-defence of our allies and our people in the region. Because that is our duty to the British people.

"It is the best way to eliminate the urgent threat. And prevent the situation spiralling further.

"This is the British government. Protecting British interests and British lives."