Thousands of anti-nuclear protesters have come together in a major rally calling on politicians to scrap Trident.

Speaker Nicola Sturgeon told the crowd at the Bairns Not Bombs demonstration in Glasgow she thought it the largest of its kind ever staged in the city.

With just over a month until the General Election, campaigners marched through the city centre before filling George Square with a sea of placards and banners.

The rally, organised by the Scrap Trident group, will be followed on April 13 by a blockade of Faslane naval base, home of the UK's nuclear deterrent.

The action is geared towards piling pressure on Westminster candidates to block the renewal of the nuclear weapon system and invest in public services.

The First Minister said: "One of the biggest decisions that MPs will take in the next Parliament is whether to waste £100 billion on renewing these morally obscene weapons.

"Broken down, that'll be around £3 billion a year, peaking at an eye-watering £4 billion in the 2020s.

"We all know that Trident is morally unjustifiable, but at a time when the Westminster parties are all committed to forcing yet more austerity on us after the election Trident is economically indefensible.

"Just think of what could be achieved with this money for the NHS, education or other public services - not just in Scotland, but across the UK."

A police estimate suggests around 2,500 people attended the rally, while organisers said the figure was closer to 4,000.

Scottish Green party co-convenor Patrick Harvie told the crowd: "There's a wave of anger up and down Scotland and throughout these islands at the idea of cutting billions from the budget that support the most vulnerable people in society, while spending even more billions on a new generation of weapons of mass destruction.

"Your job over the coming weeks is to make sure people hear the alternative voice.

"You need to take the message out day after day, to friends, family, your colleagues, your neighbours, make sure they bring the issue of Trident to the top of the political agenda when they decide how they will cast their vote.

"Let's convince everybody in this country to vote no to Trident."

Ms Sturgeon said: "All of us must put the question of Trident renewal at the top of the agenda over the next few weeks.

"The MPs you elect next month will decide whether we renew Trident.

"The choice could not be clearer. You can vote to spend £100 billion on a new generation of weapons of mass destruction.

"Or you can vote to spend £100 billion on building a fairer and more prosperous society.

"Future generations will never forgive us if we make the wrong choice."

Labour's North Ayrshire candidate Katy Clark also addressed the rally, along with Cat Boyd from the Radical Independence Campaign and Ann Henderson of the STUC.