Jeremy Corbyn has blamed Trump for Iran's seizure of two British tankers in the Gulf

Jeremy Corbyn has pointed the finger at Donald Trump after two British tankers were seized by Iran in the Gulf.

The Labour leader said Trump's decision to pull out of the nuclear deal last year was to blame for the flare up in tensions last night.

The Iranian Revolutionary Guard launched a guerilla-style attack to confiscate the British vessels as they passed through the Strait of Hormuz.

The seizures are thought to be in retaliation for the detention of the Iranian Grace 1 tanker by UK forces earlier this month.

Corbyn said: 'The seizure of these vessels is unacceptable, and the tanker that remains under Iranian control must be released. Escalation risks a slide into an even deeper conflict.

'President Trump's decision to tear up the Iran nuclear deal fuelled the risk of full-scale conflict.

'A negotiated reinstatement of the nuclear deal through the UN is essential to wind down tensions and defuse the threat of war in the Gulf.'

US President Donald Trump, speaking on the lawn of the White House yesterday, described Iran as 'nothing but trouble', but predicted the standoff would eventually work out 'very nicely'

Other senior Labour figures chimed in as news broke of the crisis in the Gulf.

Shadow Foreign Secretary Emily Thornberry echoed Corbyn's comments calling for the nuclear deal to be reinstated.

A spokesman said: 'The seizure of these vessels is totally unacceptable, as as Emily Thornberry made clear in the House of Commons this week, it is part of a deliberate strategy by Iranian hardliners to raise the stakes with the rest of the world by saying: 'If you disrupt our oil exports, we will disrupt yours'.

'This kind of escalation in rhetoric and action helps no-one on any side, and risks a slide into devastating conflict, in a country nine times the sizer of Syria.

The Stena Impero oil tanker was seized by Iranian authorities while passing through the Strait of Hormuz yesterday. An image released by a Government-funded Iranian news outlet claims to show the seized British tanker Stena Impero anchored in southern Iran

The Stena Impero was surrounded by Iranian Revolutionary Guard forces at 4pm and ordered to head north. The British registered vessel switched off its maritime tracker a short time later. A second British vessel, Medsar, abruptly changed course towards Iran around 4.45pm

'What we must instead all get to is a position where we put the Iranian nuclear deal back in place, where all parties, including the United States, return to abiding by its full terms, and where – working through the UN – we then use that as a basis for all the other issues we have to resolve with Iran.'

Labour shadow chancellor John McDonnell said the seizure of a British oil tanker was 'unacceptable' and said the solution was 'getting people back round the table'.

He said: 'The Iranian government is obviously to blame for taking the tanker, it's unacceptable behaviour and we echo what the Government has said,' he told PA on Saturday. The key issue now is getting people back round the table.

'All the military advisers that I've listened to, retired military, have been saying we've got to get back round the table, and we could play that role.

'The US destabilised the situation a bit, by pulling out of the agreement that we had, that we helped broker, and what we need to do now is act in the role of honest broker.

'But Iran's behaviour is unacceptable and they've got to release the ship.'

Labour deputy leader Tom Watson urged caution in a series of tweets: 'These reports are a matter of real concern.

'We know that some days ago there was an attempt to steer a British tanker towards Iranian waters.

'Our ships have the right of safe passage and the Stena Impero must be allowed to continue its voyage unimpeded.

'Any move to seize a British tanker would be a significant and harmful escalation of a situation where de-escalation is needed.'