Jeremy Corbyn has joined hundreds of pro-Iran protesters who gathered in London carrying banners of the Ayatollah to demand an end to 'Trump's wars'.
The former Labour leader, 76, was seen with his brother Piers Corbyn, 78, alongside supporters of the regime at a rally in Parliament Square on Saturday.
The crowds of activists gathered to condemn US and Israel's missile strikes on the capital of Tehran and other targets across the nation, The Telegraph reports.
They brandished signs bearing portraits of the Ayatollah Khamenei, Iran's supreme leader, and the slogan, 'Choose the Right Side of History'.
Other placards read 'Stop Trump's Wars' and 'No War on Iran', while some flew the country's tricolour flag, bearing the regime's Islamic emblem.
Demonstrators chanted, 'Long live the resistance! Long live Iran!', and, 'Resistance is justified when people are colonised!', as well as, 'USA are war criminals! USA are baby killers!'
Other chants included, 'Zionism is a crime, get your hands off Palestine', and, 'Zionism is terrorism', while some activists waved the Palestinian flag.
Jeremy Corbyn (centre left) was seen with his brother Piers (centre right) alongside supporters of the regime at a rally in Parliament Square on Saturday
The crowds of activists (pictured) gathered to condemn US and Israel's missile strikes on the capital of Tehran and other targets across the nation. Many bore placards (pictured) reading 'Stop Trump's Wars'
They also brandished signs (pictured) bearing portraits of the Ayatollah Khamenei, Iran's supreme leader, and the slogan, 'Choose the Right Side of History'
It is not known whether there were any arrests. The Metropolitan Police has been contacted for comment.
David Polden, 85, from Highgate, north London, said: 'It's just very dangerous to have a war in the Middle East, which the United States is determined to have.
'Killing Iranians is hardly supporting them, I would have thought.'
He said it was 'terrible' tens of thousands of Iranians had been killed by the regime in its recent crackdown on protests: 'It's a terrible regime - but so is America.'
Mr Polden said he thought the US and Iranian governments were 'equally' bad - but because America is more powerful, it can do greater damage.
The rally was organised by the Stop The War In Iran Coalition, which had urged people to gather under the slogan 'Hands Off Iran'.
The organisation said the Iranian people would be the real victims of American and Israeli strikes.
It said in a statement: 'They will lead to death and destruction in Iran and they threaten wider war across the region with unimaginable consequences.
'We must protest this madness and demand that our Government takes no part and condemns Israel's and US's catastrophic actions.'
The event was also supported by the Islamic Human Rights Commission, Jewish Network for Palestine and the Campaign for Nuclear Disarmament.
It came a few hours after hundreds of Iranian democracy activists gathered in Whitehall for a separate protest calling for the end of the Iranian government.
The rally was organised by the Stage of Freedom group, which opposes the Ayatollahs' regime and supports the American strikes.
Demonstrators gathered outside the Ministry of Defence in central London ahead of a march down to the Iranian embassy.
They waved the Iranian flag from before the Islamic regime, which features a green, white and red horizontal tricolour, with a central gold lion and sun.
One pro-democracy protester against the hardline Iranian government carried a puppet of the Ayatollah hanging from a noose.
Other attendees, who were joined by far-right activist Stephen Yaxley-Lennon, also known as Tommy Robinson, waved the Israeli flag.
Photographs were displayed outside the Iranian embassy of people killed by the country's authorities in recent protests against the regime.
Many anti-regime activists are in support of the return of the Shah, or the former monarch of Iran, Reza Pahlavi, who was ousted in the 1979 Iranian Revolution.
It came a few hours after hundreds of Iranian democracy activists gathered in Whitehall for a separate protest (pictured) calling for the end of the Iranian government
The rally (pictured) was organised by the Stage of Freedom group, which opposes the Ayatollahs' regime and supports the American strikes
Demonstrators, who were joined by far-right activist Stephen Yaxley-Lennon (pictured, at the rally), also known as Tommy Robinson, gathered outside the Ministry of Defence in central London (pictured) ahead of a march down to the Iranian embassy
One pro-democracy protester against the hardline Iranian government carried a puppet of the Ayatollah hanging from a noose (pictured)
Both rallies came as the US and Israel launched a large-scale attack on Iran on Saturday morning. Iran responded to the attack by launching missiles at Israel and four Gulf states which host US military bases: Bahrain, Kuwait, Qatar and the UAE. Pictured: Explosions from Israeli projectile interceptions over Tel Aviv on Saturday
They also call for the British government to ban Iran's Islamic Revolutionary Guard Corps (IRGC), a branch of the army set up when the Ayatollahs came to power.
Ehsan Fathi, 45, a British-Iranian national highways project manager, said he had long called for an end to the Iranian regime.
But he said events in January, which saw around 36,500 Iranians killed in the protest crackdown, had added greater urgency to his fight.
Mr Fathi said he was appreciative of American and Israeli intervention, which he said could weaken the Iranian government enough for the people to take back control.
Kima Mohajeran, 63, who was protesting with her husband Davood, 71, said she had seen videos of Iranians celebrating in the streets about the US and Israeli strikes.
She said the Stop The War protesters do not understand this is how the Iranian people feel.
Her husband said he is anti-war but that this war is not against the Iranian people but what he saw as a deadly regime, which will allow the people to take over.
The Metropolitan Police imposed conditions on both protests.
The Stop The War event was limited to a particular section of Parliament Square, while Stage for Freedom protesters had to disperse by 5.30pm.
Both rallies came as the US and Israel launched a large-scale attack on Iran on Saturday morning.
Iranian media reported explosions in Tehran just after 9.30am local time (6am GMT), with pictures showing smoke over the capital.
Explosions were also reportedly heard in other cities across the country, including Karaj, Isfahan, Qom and Kermanshah.
President Donald Trump said America had begun 'major combat operations' and urged the Iranian people to use the opportunity to overthrow the regime.
Iran responded to the attack by launching missiles at Israel and four Gulf states which host US military bases: Bahrain, Kuwait, Qatar and the UAE.
Countries across the Middle East have since locked their airspaces, amid safety concerns.
And multiple Israeli officials have since claimed Iran's Supreme Leader is dead.
Trump and Israeli President Benjamin Netanyahu have allegedly been shown a photograph of his body.
'A photo of the body was shown to Netanyahu and Trump,' reported Channel 12.
'Senior Israeli officials were informed of Khamenei's elimination. His body was recovered from the rubble of his compound,' reported public broadcaster Kan.
There has been no confirmation of Khamenei's death from Tehran.
Netanyahu said on Saturday, in a televised address to his nation, 'there are signs' Iran's Supreme Leader is dead.
He said airstrikes have destroyed Ayatollah Khamenei's compound, adding: 'All indications show this tyrant is no longer with us.'
It followed the Iranian foreign ministry's claim earlier this evening that the Supreme Leader and the country's president were both alive and well.
'They are all safe and sound,' a spokesperson told Sky News.
Israeli media outlet Channel 12 said earlier today unnamed Israeli sources revealed there were 'growing indications' the leader had been killed during this morning's air strikes or he was 'hurt at the very least'.
Officials earlier reported the strikes had caused 'very significant harm' to the leadership of the Iranian regime and its military commanders.
Khamenei had not been heard from since the US and Israel launched their dual attack.
Israeli sources said on Saturday Trump specifically targeted Iran's Supreme Leader in its first wave of joint missile strikes with Israel.
But Iranian Foreign Minister Abbas Araghch claimed the Ayatollah is alive 'as far as I know' - and denounced the strikes as 'wholly unprovoked, illegal and illegitimate'.