Jeremy Corbyn has blamed Donald Trump for escalating tensions in the Gulf as the Labour leader called for the release of the British-flagged oil tanker seized by Iranian forces yesterday.

The Labour leader tweeted: “The UK tanker under Iranian control, and its crew, must be released. Escalation risks a deeper conflict, all sides must show restraint.

“Trump tearing up the Iran nuclear deal has fuelled confrontation. Its negotiated reinstatement is essential to defuse threat of war in the Gulf.

The Stena Impero, a Swedish-owned oil tanker sailing under a UK flag was boarded by Iran’s Revolutionary Guards on Friday and then forced to sail into Iranian territory.

Penny Mordaunt, the defence secretary, has said the vessel was in Oman’s territorial waters at the time it was seized and described Iran’s actions as a “hostile act”.

Tensions high as Trump approves new Iran sanctions: In pictures Show all 17 1 /17 Tensions high as Trump approves new Iran sanctions: In pictures Tensions high as Trump approves new Iran sanctions: In pictures Iran claims that in this picture released by Iran state TV, their surface-to-air missile is seen as it shoots down a US surveillance drone EPA Tensions high as Trump approves new Iran sanctions: In pictures This photo shows US RQ-4A Global Hawk unmanned surveillance drone. A drone of this model was shot down by Iran on Thursday 21 June AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures An oil tanker is on fire after it was subject to a suspected attacked at the Gulf of Oman on June 13. The US has blamed Iran for the attack Reuters Tensions high as Trump approves new Iran sanctions: In pictures Iran claims that in this picture released by Iran state TV, debris from the downed US drone is seen after it was recovered from Iranian waters AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures Smoke billows from an oil tanker after it was subject to a suspected attacked at the Gulf of Oman on June 13 Reuters Tensions high as Trump approves new Iran sanctions: In pictures US President Trump holds up a signed executive order to increase sanctions on Iran on 24 June AP Tensions high as Trump approves new Iran sanctions: In pictures Iranian President Rouhani stated in a televised address that the White House is "afflicted by mental retardation" following the increase in sanctions on 25 June EPA Tensions high as Trump approves new Iran sanctions: In pictures An Iranian navy boat tackles the fire on the Norwegian owned Front Altair oil tanker after it was hit in a suspected attack AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures Iran claims that in this picture released by Iran state TV, debris from the downed US drone is seen after it was recovered from Iranian waters AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures Smoke billows from an oil tanker after it was subject to a suspected attacked at the Gulf of Oman on June 13 Reuters Tensions high as Trump approves new Iran sanctions: In pictures A screenshot from a video released by the US Department of Defense that the US claims to show Iranian removing an unexploded limpet mine form the hull of the Japan-owned ship that was attacked in the Gulf of Oman on June 13 Getty Tensions high as Trump approves new Iran sanctions: In pictures An item reportedly found on the Japan-owned oil tanker that was attacked on June 13 in the Gulf of Oman AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures A handout photograph from the US Department of Defense shows a composite material that the US claim was left behind on the hull of the Japan-owned oil tanker following the removal of an unexploded limpet mine Getty Tensions high as Trump approves new Iran sanctions: In pictures A view from the cabin of an Iranian navy boat as it tackles the fire on the Norwegian owned Front Altair oil tanker after it was hit in a suspected attack EPA Tensions high as Trump approves new Iran sanctions: In pictures Release by US government A picture released by U.S. Central Command shows damage to the hull of the oil tanker Kokuka Courageous. The picture suggests that the ship is 'likely' to have been hit by a mine as the US Secretary of State Mike Pompeo moves to blame Iran for the suspected attack Reuters Tensions high as Trump approves new Iran sanctions: In pictures Smoke billows from an oil tanker after it was subject to a suspected attacked at the Gulf of Oman on June 13 Reuters Tensions high as Trump approves new Iran sanctions: In pictures Release by US government A picture released by U.S. Central Command shows damage to the hull of the oil tanker Kokuka Courageous. The pictures suggests that the ship is 'likely' to have been hit by a mine as the US Secretary of State Mike Pompeo moves to blame Iran for the suspected attack EPA

Earlier today John McDonnell, the Labour shadow chancellor and Mr Corbyn’s closest political ally, said the Iranian government was “obviously to blame for taking the tanker, it’s unacceptable behaviour and we echo what the Government has said”.

But his leader has taken a different approach to the growing diplomatic crisis and has instead laid the blame at the US government’s door.

Mr Trump decided to withdraw America from the nuclear deal with Iran last year, and instead ramped up sanctions on Tehran.

Many analysts believe Iran captured the Stena Impero in retaliation for Britain impounding Grace 1, an Iranian oil ship which was detained by Royal Marines off Gibraltar.

The British government has alleged the ship was on its way to deliver fuel to Syria, breaching EU sanctions.

A spokesman for Iran’s highly influential Guardian Council has been quoted describing Britain’s detention of Grace 1 as part of an “illegitimate economic war” and therefore Iran’s response in seizing the Strena Impero was part of “the rule of reciprocal action... well-known in international law”.

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However, Iran’s increasingly aggressive action in the Gulf has also targeted US ships and included the Revolutionary Guards shooting down a US drone last month.

In an effort to pressure the Iranian regime, a senior diplomat has been summoned to the Foreign Office and Jeremy Hunt, the foreign secretary has “expressed extreme disappointment” in a phone call with his Iranian counterpart Javad Zarif.

Mr Corbyn has in the past been accused of being soft on Iran, with some critics pointing to his years spent presenting and contributing to programmes on Press TV, an English-language channel run and funded by Tehran.

Last month he cautioned against rushing to blame Iran for a spate of attacks on oil tankers in the Gulf without first gathering “credible evidence” of their culpability.