LONDON, UKinfo-icon: British Prime Minister Theresa May faced a backlash from the domestic opposition after launching military strikes on Syriainfo-icon without consulting parliament.

As the conservative leader explained her rationale for the air strikes, opposition parties claimed the attacks were legally dubious, risked escalating conflictinfo-icon and should have been approved by lawmakers.

The shadow of the 2003 invasion of Iraqinfo-icon still lingers in the corridors of Britaininfo-icon's parliament, when MPs backed then-prime minister Tony Blair in joining USinfo-icon military action.

"Bombs won't save lives or bring about peace," said Jeremy Corbyn, the veteran leftist leader of the main opposition Labour Party. "This legally questionable action risks escalating further... an already devastating conflict. Theresa May should have sought parliamentary approval, not trailed after Donald Trump."

Corbyn has written to May seeking assurance that there would be no further bombing raids and urged the government to negotiate a pause in the Syrian civil warinfo-icon.

The British, US and French bombings on Saturday followed an alleged chemical weaponsinfo-icon attack on the rebel-held town of Douma on April 7.

May's government has insisted the punitive strikes were legal, releasing a statement that said they were aimed at alleviating the "extreme humanitarian suffering" of the Syrian people by reducing the chemical weapons capabilities of President Bashar al-Assad's regime.

"The UK is permitted under international law, on an exceptional basis, to take measures in order to alleviate overwhelming humanitarian suffering," the statement said.

It added that it believed the Syrian government had committed a "war crime and a crime against humanity" with chemical weapons use and that attempts to find a unified international approach through the

United Nationsinfo-icon had been blocked by Damascus-ally Moscow.

May will face questions from MPs on Monday, when parliament reconvenes after a break.

Stop the War, a pacifist coalition once chaired by Corbyn, has called a demonstration outside the British parliament on Monday to protest against the strikes.

The group said it "strongly condemned" the action and accused May of "sanctioning killing" at Trump's behest.

Deploying the armed forces is a prerogative power, meaning the prime minister can launch action without backing from MPs.

But after the Conservatives entered office in 2010, the government suggested that since the 2003 vote on Iraq, a convention had emerged that MPs should have a say, except in cases of emergency.

British MPs voted against taking military action against Damascus in 2013, in what was widely viewed as an assertion of parliamentary sovereignty on the use of force.

David Cameron, who was prime minister in 2013, tweeted on Saturday: "As we have seen in the past, inaction has its consequences".

Lawmakers backed action in Iraq in 2014, and again in Syria in 2015, strictly limiting strikes in both countries to targets of the Islamic Stateinfo-icon terrorist group.

Four British Tornado jets fired Storm Shadow missiles at a Syrian military base suspected of holding chemical weapons components.

Scottish First Minister Nicola Sturgeon said Syria's use of chemical weapons could not be tolerated but questioned whether the strikes would halt their use or contribute to ending the civil war.

"This action risks not just further escalating the civil war in Syria but also a dangerous escalation of international tensions," said the leader of the left-wing Scottish National Party, the third-biggest force in the British parliament.

Both Syria and Russiainfo-icon have denied all responsibility for the alleged chemical attacks.

Vince Cable, leader of the Liberal Democrats, the fourth-biggest party in parliament, accused May of "riding the coat-tails of an erratic US president".

"It shows a weak government putting short term political expediency before democracy and in so doing further diminishing the standing of Britain in the worldinfo-icon," Cable said.

The Green Party, which has one MP, said May had "trampled over parliamentary democracy" and demanded a vote in the House of Commons on the strikes.

However, there was some support for May. The centre-right conservatives rely on the support of the Democratic Unionist Party, Northern Ireland's biggest party, for a majority in parliament.

DUP leader Arlene Foster said the air strikes were "limited but proportionate and justified".

Tom Tugendhat, the conservative chairperson of parliament's foreign affairs scrutiny committee and a former armyinfo-icon officer, said May had "taken the correct decision".

Peter Felstead, editor of Jane's Defence Weekly, said he did not think May would face a "serious backlash", as the strikes ultimately were politically and operationally "the right thing to do".

"Corbyn will rail against military action, claiming it could widen the conflict, but if he won't sanction military action against a regime that is using chemical weapons on its own people, when would he ever sanction it?" he told AFP.

"If the West had acted against Assad's chemical weapons attacks in 2013, we might not have had to embark on military action now."