Philip Hammond, the Defence Secretary, will reveal the scheme to build a new nuclear deterrent in a move which will cause tensions with the Liberal Democrats.

He will announce a deal ordering nuclear reactors for a new class of submarines to replace the current Vanguard fleet, which carries Britain's Trident nuclear arsenal.

The decision is the most public statement yet that the Government is committed to a full-scale replacement of Trident - something opposed by the Lib Dems, who want a cheaper way of maintaining nuclear weapons.

The Lib Dems had a manifesto commitment against renewing Trident, so this announcement is going to annoy them. But another £1 billion to be wasted on pointless phallic symbols of defence while actual defence forces are being wound down. I think polticians priorities are madness.

keep to the Fen Causeway