The proposals will be published after a cabinet meeting on Monday. Government members had already been briefed "in detail" by Defence Secretary Des Browne and Foreign Secretary Margaret Beckett, he added.

Blair's government is widely expected to give the green light to developing a replacement for the US-built missiles, which are carried on four Royal Navy Vanguard class submarines, one of which is always on patrol.

Trident will become obsolete in the mid-2020s. A successor would require many years of development and according to observers could cost up to 25 billion pounds (37 billion euros, 46 billion dollars).

Blair and his finance minister Gordon Brown have both indicated that they back the maintenance of an independent nuclear deterrent, despite the costs.

But opposition to nuclear weapons and power is historically a central plank of Labour policy and Blair may have a fight on his hands to push through his proposals.

Northern Ireland Secretary Peter Hain and International Development Secretary Hilary Benn are reportedly against Trident and about 120 backbench lawmakers from Blair's governing Labour Party have lobbied him to rethink.

In the 1980s, Labour leaders like Neil Kinnock spoke at marches organised by the Campaign for Nuclear Disarmament and the issue figured prominently in the party's general election manifestos.

Since Blair took over as leader in 1994 and took the left-wing party to the centre ground, however, that position has been reversed.

Blair is also in favour of new nuclear power stations to help address Britain's future energy needs.

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