Sir Keir Starmer has said there was a “sense of real relief” at the ceasefire in the US-Iran conflict but a lot of work still needed to be done to make the peace deal last and restore oil and gas supplies through the Strait of Hormuz.
The Prime Minister, who was visiting an air base in Saudi Arabia, said he wanted to ensure the economic impact of the war was minimised by getting the strait open again.
US President Donald Trump had threatened to obliterate Iran’s power plants and bridges if a deal could not be reached to reopen the route to shipping, but less than two hours before his deadline, he said a ceasefire had been agreed.
Iran closed the strait again on Wednesday night in response to Israeli attacks on the Hezbollah militant group in Lebanon.
The US said the closure was unacceptable, and press secretary Karoline Leavitt repeated Mr Trump’s “expectation and demand” it be reopened.
Sir Keir said it was still “early days” after the overnight announcement.
He said there was still work to do to ensure “this ceasefire should be not a temporary ceasefire but a permanent ceasefire”.
He added: “On top of that, we have to acknowledge that this war was not our war, but my job is to protect the UK.
“It’s already had an impact on the UK, and it’s very important we get the Strait of Hormuz open. There’s a lot of work to do there.”
Sir Keir’s refusal to let the US have free rein on the use of British bases to launch raids against Iran has severely strained the Prime Minister’s relationship with Mr Trump.
Asked whether his relationship with the US president was “in tatters”, Sir Keir said: “I’ve acted as you would expect of a British Prime Minister, which is by being absolutely focused on what is our national interest, and that’s why I’ve applied my principles and my values throughout.
“And my principles and values made sure that our decisions were that we wouldn’t get involved in the action without a lawful basis, without a viable, thought-through plan.”
The ceasefire announcement triggered a fall in global oil prices and stock markets rallied after weeks of economic turmoil.
The US-Israeli strikes on Iran and Tehran’s response, including targeting Gulf states and effectively closing the Strait of Hormuz, had sent fossil fuel prices soaring around the world.
Petrol and diesel costs for motorists in the UK rose sharply after Mr Trump launched his military action.
The average price of diesel was 190.6p on Wednesday morning, up 34% since February 28 when the US-Israeli campaign began, while average unleaded prices reached 157.7p, up 19%, the RAC said.
A joint statement by world leaders including Sir Keir said they would “contribute to ensuring freedom of navigation in the Strait of Hormuz”.
The statement, signed by the leaders of the UK, France, Italy, Germany, Canada, Denmark, the Netherlands and Spain and the presidents of the European Commission and European Council, welcomed the ceasefire.
“We strongly encourage quick progress towards a substantive negotiated settlement,” they said.
“This will be crucial to protect the civilian population of Iran and ensure security in the region.
“It can avert a severe global energy crisis.
“We support these diplomatic efforts. To this end, we are in close contact with the United States and other partners.
“We call upon all sides to implement the ceasefire, including in Lebanon.”
Israel maintained its attacks on Lebanon, the base for Iran-backed Hezbollah, claiming it was not covered by the ceasefire deal.
US vice president JD Vance said there was now a “fragile truce”, with reports from the Gulf of missile or drone raids on Kuwait and the United Arab Emirates, while Iran claimed its Lavan Island oil refinery had come under attack.
Announcing the two-week pause in the bombing campaign, Mr Trump said Tehran proposed a 10-point plan that provided “a workable basis on which to negotiate”.
But he wrote that US forces would be “hangin’ around in order to make sure that everything goes well”.
Tehran believes the deal will keep the strait under Iranian control, allowing it to levy tolls on shipping.
Pakistan’s prime minister Shehbaz Sharif said he had invited Iranian and US officials to Islamabad for talks on Friday.
Mr Trump wrote on his Truth Social platform that it was “a big day for World Peace!” and predicted “the Golden Age of the Middle East”.
