Jeremy Corbyn has called for a war powers act that would stop Theresa May from launching bombing raids without first consulting MPs.
The Labour leader was responding to the news America, Britain and France launched airstrikes in Syria early on Saturday morning.
Mr Corbyn, who has issued a plea for a independent UN-led investigation of last week’s chemical weapons attack in Syria, has said the prime minister should have strived for parliamentary approval before instigating the action.
The opposition leader called for a proper debate in parliament on Monday which concludes with a vote on action in Syria.
"I think parliament should have a say in this and I think the Prime Minister could have quite easily done that," Mr Corbyn told the Andrew Marr Show on Sunday.
"She took a decision some time last week that we were going to work with Macron and Trump in order to have an impact on the chemical weapons establishment in Syria.
"She could have recalled parliament last week - it is only the PM who can recall parliament - or she could have delayed until tomorrow when parliament returns. There is precedent over previous interventions when parliament has had a vote".
The MP for Islington North, who also called for a war powers act back in 2016, continued: "I think what we need in this country is something more robust like a war powers act so governments do get held to account by parliament for what they do in our name".
In April 2016 ministers deserted plans to introduce a war powers act that would have enshrined a commitment to gain parliamentary approval before deploying British troops in conflict into law.
Calls for a war powers act mounted after the military interventions in Iraq, Afghanistan, and Libya. However ministers resolved such a statute would curb their freedom of action, make them susceptible to potential legal action, and result in them becoming entangled in arguments about the definition of training and combat missions.
Across the Atlantic in the US, the War Powers Act is a federal law intended to check the president's power to commit the country to an armed conflict without the consent of Congress. The War Powers Resolution requires the president to notify Congress within 48 hours of committing armed forces to military action.
Mr Corbyn's plea for a war powers act comes after he branded airstrikes on Syria legally questionable and accused Ms May of “trailing after Donald Trump”.
On Saturday, he condemned the attack aimed at reducing the Syrian government's chemical weapons capabilities and claimed it would make real accountability for war crimes less likely.
Mr Corbyn said: “Bombs won’t save lives or bring about peace. This legally questionable action risks escalating further, as US defence secretary James Mattis has admitted, an already devastating conflict and therefore makes real accountability for war crimes and use of chemical weapons less, not more likely.”
Ms May sidestepped a non-binding constitutional convention which dates back to the 2003 invasion of Iraq by launching strikes without prior approval from parliament. However, the PM insisted speed was essential and the action against Syria was in the UK's national interest.
Ms May said the attacks were “right and legal” and “gave a very clear message to the regime”, in a press conference on Saturday morning.
Allied air strikes were carried out in Syria in response to a suspected poison gas attack that saw 40 people killed in the town of Douma near Damascus last Saturday.
The intervention is the largest so far by Western powers in the Syrian conflict, with more than 100 missiles launched at various targets. Labour has been opposed to a military strike on Syria since the chemical weapons attack on Douma.
Russia, an ally of the Syrian government led by president Bashar al-Assad, has warned the strikes will have “consequences”. Russian president Vladimir Putin claimed the attack will aggravate the humanitarian crisis in the country.
