Thousands march in protest against Trident nuclear system renewal

Thousands of people opposed to the renewal of the multibillion-pound Trident nuclear system marched through London in the biggest demonstration of its kind for a generation.

Anti-nuclear protesters from across the UK armed themselves with placards and banners as they braced the bitter winds whipping around the centre of the capital to spread their message.

The group - estimated by stewards to run into "many tens of thousands" - were joined on the marches by SNP leader Nicola Sturgeon and her Plaid Cymru counterpart Leanne Wood, with organisers hoping the event would send a strong message of growing support against renewing the nuclear weapons system.

The Ministry of Defence has estimated acquiring four new submarines to carry the Trident deterrent will cost £31 billion over the course of the 20-year procurement programme, with a further £10 billion set aside to meet any additional unexpected cost increases.

Addressing the crowd as the rally continued to gather in Trafalgar Square, Ms Sturgeon described Trident as "immoral" and "impractical".

She said: "It is the norm in the world today to be nuclear-free. It is the exception to the rule to possess nuclear weapons, let that ring out loudly and clearly.

"The use of nuclear weapons would bring about human devastation and suffering on an unimaginable scale."

She said the SNP would be making Trident a political issue at forthcoming elections.

Former Green Party leader Caroline Lucas described nuclear weaponry as "a cold war relic".

She said: "To contemplate using nuclear weapons is both illegal and immoral."