Boris Johnson, the Foreign Secretary, has suggested Britain could bypass the House of Commons and join the United States in taking military action against the Syrian regime if it is asked.

Mr Johnson added it would be “very difficult to say no” if Donald Trump’s administration asks the UK for help in taking action against Bashar al-Assad’s regime in response to another chemical attack.

Asked on the BBC’s Radio 4 Today programme whether he could envisage taking military action in the region, he replied: “I think it will be very difficult if the United States has a proposal to have some sort of action in response to a chemical weapons attack, and if they come to us and ask for our support, whether it’s with submarine-based cruise missiles in the [Mediterranean], or whatever it happens to be, as was the case back in 2013, it would be in my view, and I know this is also the view of the Prime Minister, it would be very difficult for us to say no.”

Pressed further on whether the Foreign Secretary would seek approval in the Commons for such a strike, Mr Johnson added: “I think that needs to be tested. As I said I think it would be very difficult for us to say no. How exactly we were able to implement that would be for the Government, the Prime Minister.

“But if the Americans were once again to be forced by the actions of the Assad regime – don’t forget, it was Assad who unleashed murder upon his own citizens with weapons that were banned almost 100 years ago – if the Americans choose to act again and they ask us to help, as I say, I think it would be very difficult to say no.”

Asked whether Theresa May agreed with Mr Johnson that it would be difficult for the UK to say no to a US request for assistance in military action against the Assad regime, the Prime Minister’s official spokesman said the Foreign Secretary was restating a position he had already given to Parliament on 18 April – the day the Prime Minister announced the snap general election.

They added: “All we have stated previously is that the US have been clear that they are not planning any further strikes, but they could reconsider if the Syrian regime uses chemical weapons again and anything beyond that is hypothetical.”

His comments come after US President Donald Trump earlier this month ordered the firing of 59 Tomahawk Cruise missiles from the USS Porter and USS Ross into the Sharyat airfield, in western Homs, in retaliation to the use of chemical weapons on civilians, allegedly by Bashar al-Assad’s dictatorial regime.

Following the chemical attack, and the pictures of dying children that accompanied it, Mr Johnson led an unsuccessful attempt to persuade G7 leaders to implement further economic sanctions on Russia for its continued support of the Syrian dictator.

At the time of the assault Michael Fallon, the Defence Secretary, said Downing Street was fully behind the US but added it is unlikely any further military action will be taken.

In pictures: US missile strike against Syria Show all 7 1 /7 In pictures: US missile strike against Syria In pictures: US missile strike against Syria The guided-missile destroyer USS Porter (DDG 78) launches a tomahawk land attack missile in the Mediterranean Sea AP In pictures: US missile strike against Syria The United States military launched at least 50 tomahawk cruise missiles at al-Shayrat military airfield near Homs, Syria, in response to the Syrian military's alleged use of chemical weapons in an airstrike in a rebel held area in Idlib province EPA In pictures: US missile strike against Syria Shayrat airfield in Syria Getty Images In pictures: US missile strike against Syria US Navy guided-missile destroyer USS Ross (DDG 71) fires a tomahawk land attack missile in Mediterranean Sea Reuters In pictures: US missile strike against Syria US Navy guided-missile destroyer USS Ross (DDG 71) fires a tomahawk land attack missile in Mediterranean Sea Reuters In pictures: US missile strike against Syria President Donald Trump speaks at Mar-a-Lago in Palm Beach, Fla., after the US fired a barrage of cruise missiles into Syria in retaliation for this week's gruesome chemical weapons attack against civilians AP In pictures: US missile strike against Syria Syria's President Bashar al-Assad Reuters

Mr Fallon added that the US strike against the Syrian airbase near Homs was intended to deter Bashar al-Assad from carrying out any further chemical weapon attacks but was not the start of a new military campaign.

“We don’t see last night’s strike like that,” he said. “We’ve not asked to be involved in this, this was not a matter for the coalition that’s in Syria and Iraq fighting Daesh.”