British opposition Labour Party leader Jeremy Corbyn said on Saturday that Prime Minister Theresa May should have sought approval from parliament before ordering cruise missile strikes against Syria.
And a significant body of information including intelligence indicates the Syrian Regime is responsible for this latest attack.
Cabinet ministers have agreed on a "need to take action" against Syria, following a suspected chemical weapon attack that claimed the lives of dozens of people in the Damascus suburb of Douma.
But our efforts have been repeatedly thwarted.
She added that the strikes were not about "regime change".
"She had said this attack was not at the Syrian government or to intervene in a civil war or the regime change".
May reiterated that Britain made use of every possible diplomatic means to stop the use of chemical weapons, but there was no response and "so there is no practicable alternative to the use of force to degrade and deter the use of chemical weapons by the Syrian regime".
The strike, conducted with the United States and France, was "limited and targeted", created to minimise any civilian casualties, May said.
"Given the context of the recent global response to the use of a nerve agent in the United Kingdom, the clear targeted objective of the strikes, and the repeated blocking by Russian Federation of diplomatic solutions through the UN, we believe the Prime Minister was justified in standing with our American and French allies in this concerted action".
At this time, my thoughts are with our fearless British servicemen and women - and our French and American partners - who are carrying out their duty with the greatest professionalism.
At a press conference in Downing Street, Mrs May said: "There is no graver decision for a prime minister than to commit our forces to combat and this is the first time I have had to do so".
I have done so because I judge this action to be in Britain's national interest. That is what our country has always done.
The UK has begun air strikes against Syrian chemical weapons sites. We would have preferred an alternative path. And what we will continue to do.