Labour splits over military action in the Middle East have been torn open after senior party figures backed US missile strikes in defiance of Jeremy Corbyn.

After the Labour leader criticised the strikes as risking enflaming the Syrian conflict, a string of former shadow cabinet members voiced their support for action.

Hilary Benn, whose departure from the frontbench sparked a leadership challenge against Mr Corbyn, said he hoped Syrian dictator Bashar Assad might now “think twice” about using chemical weapons, while ex shadow minister Michael Dugher mocked his leader’s “slow response” to the strikes and Mary Creagh accused leftwingers of preferring “inaction..to stopping a murderous tyrant”.

There were also reports that Mr Corbyn may have disagreed with advice given by his current shadow defence secretary Nia Griffith’s in formulating his response, while Deputy Leader Tom Watson said chemical weapon attacks from the Assad regime “must have consequences”.

Labour infighting also flared ahead of the last vote to take action against the Islamic State in Syria in 2015, with Mr Corbyn opposing it while Mr Benn made a passionate speech that was hailed by supporters of intervention.

As Mr Corbyn was still considering how to respond on Friday morning, Mr Benn tweeted: “Let's hope Syria will now think twice before deciding to gas its own people again. Priority must be humanitarian assistance for civilians.”

Hilary Benn receives standing ovation

He was backed by London Labour MP Wes Streeting. Meanwhile, former Treasury minister Angela Eagle said: “The limited, targeted action taken against Syrian air assets today was morally justifiable in response to a crime against humanity...and compliant with our Responsibility to Protect.

She added: “Inaction has a cost in lives too.”

John Woodcock MP also called the action “proportionate” calling for the UK to take a lead ensuring aid can reach Syrians.

Following on from recent public criticism of Labour’s communications operation, Mr Dugher launched an attack on the leader’s chief spokesman Seumas Milne.

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

The former shadow transport secretary said: “Stop criticising Corbyn's slow response: it takes time for Seamas [sic] to run the draft statement by the Kremlin, Stop the War + the Morning Star.”

Ex-international development secretary Mary Creagh said: “UK govt right to support US action against Homs airbase after Idlib chemical weapons attack on civilians. Hope this ends Assad's impunity.

“Our inaction in 2013 allowed Assad's war crimes against his people to continue unchecked. 500 000 dead 12m refugees.”

Her words were later backed by ex-home secretary Jacqui Smith on Twitter. Leading Ms creagh to go further saying: “Amazing how some sections of the left- and right -prefer inaction in Syria to stopping a murderous tyrant and his genocide”.

Stella Creasy, who faced intense criticism from the leftwing activists after backing strikes in Syria in 2015, said on Friday: “This is what is happening in Syria. World cannot ignore suffering Assad inflicting. UN now must lead what happens next to protect civilians.”

In a statement released on Friday, Mr Corbyn said: “Unilateral military action without legal authorisation or independent verification risks intensifying a multi-sided conflict that has already killed hundreds of thousands of people.