By Agencies

Rejecting accusations of US pressure, UK PM says involvement in Saturday's coordinated attack was in national interest.

Britain's prime minister has defended UK's decision to launch coordinated strikes with American and French forces, in an attempt to "further prevent the use of chemical weapons" in Syria.

Speaking at the House of Commons on Monday, Theresa May said Britain's involvement in Saturday's attacks on Syria's alleged chemical weapons sites was in the national interest.

"We have not done this because [US] President [Donald] Trump asked us to do so," she told parliament.

"We have done it because we believe it was the right thing to do and we are not alone."

Many opposition MPs have questioned May's decision to join the attack without seeking parliamentary approval.

Jeremy Corbyn, leader of the opposition Labour Party, reiterated his stance that May is "accountable to the parliament - not to the whims of the US president".

He also questioned the legal justification of the attack, saying it was not in line with the UN Security Council's charter.

"There is no more serious issue than the life and death matters of military action," he said on Monday.

"It is right that parliament has the power to support or stop the government from taking planned military action."

Vote on the strike

For its part, the Scottish National Party says it will force a vote on the issue.

Since the Iraq war in 2003, under Britain's constitutional convention parliament expects an opportunity to debate the matter if British troops are to be involved in military combat.

Saturday's strikes, which came in response to a suspected chemical attack on the former rebel stronghold of Douma on April 7, targeted the sites near Damascus as well as in the province of Homs.

Confirming Britain's involvement in the attack in her speech, May said: "We would have preferred an alternative path. But on this occasion there is none."

She said the attacks were not about "regime change" or "intervening in a civil war", but were to "deter the use of chemical weapons" by the Syrian government.

After her statement, May was expected to ask the speaker of the parliament to grant an emergency debate, followed possibly by a non-binding vote.