MPs have begun debating Trident ahead of a vote later tonight that will determine whether or not to renew Britain’s nuclear deterrent.
This is Theresa May’s first appearance at the Commons as Prime Minister.
She has told MPs that failing to renew Trident would be “an act of gross irresponsibility”, the BBC reports.
What is Trident?
Trident came into use in the 1990s and it refers to the missiles on board four Vanguard-class submarines.
Each submarine carries up to eight Trident missiles, which can be fitted with a number of warheads.
At any one time, there is a British submarine with nuclear weapons on patrol.
This silent submarine would still be able to launch an aggressive attack in the event of the nation’s traditional defences failing.
Each warhead is thought to be eight times as powerful as the atomic bomb.
How much will it cost?
The submarines are due for renewal by the 2030s and it will cost around £41bn with a £10bn contingency.
Labour leader, Jeremy Corbyn opposes renewal but his party’s MPs will get a free vote on the issue.
However, trade unions, Unite and GMB, are back renewal because of the jobs associated with it.
Those voting for it, believe Trident is important for national security while those who are against renewal say that if we have nuclear weapons we are more likely to use them.