Greenpeace activists have scaled a crane next to the House of Parliament and hung a huge banner from it declaring 'TONY loves WMD'.
The protest came as MPs prepar to vote today (Wednesday 14 March) whether to renew Britain's nuclear weapons system and commit Britain to nuclear arms for the next 50 years.
The four volunteers aim to occupy the crane until the vote takes place. They also hope to telephone as many MPs as possible urging them not to support new weapons of mass destruction.
One of the volunteers on the crane, Cat Dorey, said: "Trident is a cold war relic designed to destroy Russian cities. If MPs buckle under pressure from Tony Blair and vote to renew it, the repercussions will be felt around the world. We can't oppose proliferation of WMD if we're building them at home."
She continued: "The government promised a national debate on Trident but this is being rushed through quicker than a shotgun wedding. The real threat is climate change and the billions earmarked for Trident could help make Britain the world's first low carbon economy. We're phoning MPs from the crane and asking them to respect the will of the country and vote against Tony Blair's WMD programme."
A recent poll commissioned by Channel Four found that three quarters of the public oppose government replacing Trident now. Church leaders have also written to MPs ahead of the vote, expressing their opposition.
A report from Greenpeace released last week estimated the true cost of building a new generation of nuclear weapons to replace Trident will be at least £76bn and could rise as high as £100 billion. These figures contrast starkly with the £15-20bn figure the government has previously stated will be the cost of Trident replacement.
The report details how government has only included the design and building costs of the submarines and not the far higher price of maintaining and developing the nuclear weapons system over its lifetime.