By Saturday evening, more than 3,600 people had signed an online petition on Blair's own own website urging him to "champion the Nuclear Non-Proliferation Treaty, by not replacing the Trident nuclear weapons system".

That follows a series of polls for CND suggesting a majority of Britons are against replacing Trident and want any decision to be made by parliament alone amid fears the government will simply try to rubber-stamp the plans.

A parliamentary vote is due in the new year, but the vote is likely to be "whipped" -- where lawmakers are told to toe the party line rather than follow their consciences in a free vote.

Between now and then, CND, whose push for unilateral nuclear disarmament at the height of the Cold War in the 1980s was also Labour party policy, promises to lead the public debate.

CND's chairwoman Kate Hudson told AFP their 32,000-strong membership has been bolstered by an extra 1,000 in recent months, directly over concern about Trident.

"What's really remarkable is how the debate has developed and many people who thought nuclear weapons were necessary during the Cold War now think they're not," she said.

"There's been a big shift in public and political opinion."

CND's fight begins soon after the government's plans are published on Monday morning, with the delivery of its alternative proposals to Blair's Downing Street office in central London.

His administration has had early warnings of the strength of feeling.

Scrapping Trident was one of the issues at a march involving tens of thousands of people in Manchester, northwest England, before Labour's annual conference in September.

At the conference itself, there was outrage among Labour left-wingers and trade unionists and claims the party hierarchy was trying to gag opponents by refusing to allow grassroots delegates to discuss Trident at all.

On October 1, protesters began a year-long peaceful blockade of the Royal Navy's nuclear submarine base in Faslane, western Scotland, where a peace camp has been based since 1982.

And just last week, protesters blockaded the country's main atomic weapons base accusing Blair of hypocrisy for opposing the nuclear ambitions of countries like Iran while pushing Britain's own.

Blair and the man tipped to succeed him before September next year, finance minister Gordon Brown, favour replacing Trident, with the government line that a nuclear deterrent is a key "insurance policy" in an uncertain world.

Campaigners reject that assertion, arguing instead that Britain should take the lead on nuclear disarmament to prevent proliferation in states like North Korea and Iran.

The estimated 25 billion pounds (37 billion euros, 46 billion dollars) it could cost to replace Trident could instead be channelled into health and social care programmes as well as the fight against global warming, they argue.

The missiles, which are due to become obsolete in the mid-2020s, are carried on four Royal Navy Vanguard class submarines, one of which is always on patrol.

There are signs, though, that Blair is aware of the potential backlash and he could concede some ground.

Saturday's Financial Times said the prime minister would indicate that the number of submarines and 200 or so stockpiled warheads could be cut in the future, to reduce the potential replacement costs.

Related Links
-