The leader of Britain’s Labour Party has once again criticized Prime Minister Theresa May for joining the United States and France in strikes against Syria without any parliamentary approval.

Corbyn said that it was time for the parliament to "assert its authority" over UK military action after it was not consulted over last week's air strikes on Syria. He further insisted that May had shown "flagrant disregard" for the convention that MPs should be consulted beforehand on foreign interventions.

He said May had "tossed aside" the precedent, set by the 2003 Iraq War vote, because it was "inconvenient."

During a six hour debate at the Westminster on Monday, Corbyn said the prime minister must be accountable to the British parliament not to any foreign head of state or the "whims" of a president.

He described the chemical attack in Douma as “horrific”, adding, “this statement serves as a reminder that the Prime Minister is accountable to this Parliament, not to the whims of the US President.”

In the early hours of Saturday, the US, Britain and France launched a barrage of missile attacks against Syria in response to what they claim to have been a chemical attack by the Syrian government in the town of Douma in the suburb of Damascus on April 7.

Corbyn said, “Her predecessor [David Cameron] came to this House to seek authority for military action in Libya and in Syria in 2015, and the House had a vote over Iraq in 2003.”

“There is no more serious issue than the life and death matters of military action. It is right that Parliament has the power to support or stop the Government from taking planned military action,’ he added.

A number of lawmakers also accused May of ignoring the parliament and not seeking its approval for missile strikes on Syria.

In response, May said her government used its judgment about how best to protect the security and interests of the UK in making the decision to join the US-led coalition.

“The speed with which we acted was essential in co-operating with our partners to alleviate further humanitarian suffering and to maintain the vital security of our operations,” May said.

The decision required the evaluation of intelligence “much of which was of a nature that could not be shared with Parliament”.