Anti-nuclear campaigners opened a new front yesterday in the fight against Tory plans to splash £100 billion on weapons of mass destruction that are as “useful as bubonic plague.”

Leaders of the three main political parties had skipped Parliament for Scotland in a bid to shore up the campaign against Scottish independence.

But activists filled the void in the heart of Westminster to launch Rethink Trident — a new push to reverse plans to retool the nuclear weapons arsenal and instead put Britain at the heart of global disarmament.