Donald Trump's libertarian supporters across the world desert him over Syria air strikes

Isolationist backers of the former reality show host, including Marine le Pen and Nigel Farage, condemn President for acting like 'policeman of the world'

Nigel Farage campaigned on behalf of President Trump, but has condemned his recent cruise missile assault on a Syrian airbase (Getty)

Donald Trump's cruise missile strike against a Syrian air base has prompted criticism from a series of his high-profile libertarian supporters at home and abroad.

International figures including far-right French presidential candidate Marine Le Pen and long-term Trump ally Nigel Farage broke ranks to condemn an attack Ms Le Pen called "horrible".

The attack also estranged figures across the American isolationist and libertarian right, including veteran senator Rand Paul and alt-right figurehead Richard Spencer.

In a television interview with BFM TV, Front National's Marine Le Pen said: "Trump was elected by announcing that the United States would no longer be the policeman of the world, would no longer interfere.

"The facts are appalling in Syria. It takes an international commission to conduct an independent investigation."

Ms Le Pen, currently slated to finish a distant second in the French Presidential election on a far-right anti-immigration ticket, also cast doubt on Mr Trump's motivation for the bombings.

The President said he hoped the strikes would "prevent and deter the use of deadly chemical weapons" like those allegedly used by the Syrian Arab Army to kill over 80 people near rebel-held Idlib. But Ms le Pen compared this explanation to the non-existent weapons of mass destruction used to justify the US invasion of Iraq in 2003.

Former Ukip chief Nigel Farage has been even closer to the new US President than Ms Le Pen. Mr Farage spoke at the billionaire tycoon's mass rallies, and was the first British politician to visit Trump Tower after Hillary Clinton's shock defeat.

But on Friday, he said: “I think a lot of Trump voters will be waking up this morning and scratching their heads and saying 'where will it all end?'

“As a firm Trump supporter, I say, yes, the pictures were horrible, but I'm surprised. Whatever Assad's sins, he is secular."

Pro-Trump politicians in Italy have also criticised the strikes, with Northern League leader Matteo Salvini describing the assault as "a bad idea, big mistake, and a gift to Isis" in a Facebook post.

And the shift against President Trump was even starker at home. Writing for Fox News, leading libertarian Senator Rand Paul fiercely condemned the "unconstitutional rush towards war".

Though they played golf together last weekend, the President has previously described Senator Paul as "truly weird" and "a spoiled brat without a properly functioning brain", and has never had the full support of the man he defeated in the Republican primary race.

But Mr Trump has also reportedly sparred with right-hand man Steve Bannon over the decision to bombard a Syrian airbase with cruise missiles.

"Steve doesn't think we belong [in Syria]," an aide to the chief strategist told NY Magazine.

The President is reportedly considering sacking Mr Bannon as chief strategist, with his about-face on Syrian intervention just the latest issue to drive a wedge between the two politicians.

Media figures previously sympathetic to Mr Trump have also queued up to blast him for the assault which left fifteen Syrian soldiers and civilians dead, including four children.

Anne Coulter has been one of Mr Trump's staunchest supporters on the Fox News circuit, but the conservative pundit wrote on Twitter: "Those who wanted us meddling in the Middle East voted for other candidates.

“Trump campaigned on not getting involved in Mideast. Said it always helps our enemies & creates more refugees. Then he saw a picture on TV.”

White nationalist Richard Spencer, who coined the phrase "alt-right", said his support for President Trump was now dead in the water, while influential blogger Paul Joseph Watson also announced he was stepping off the "Trump train".