Trident contracts worth £350m to be unveiled

The Ministry of Defence will announce later that it is awarding £350m in contracts to design the next generation of nuclear-armed submarines.

The contracts are part of £3bn already set aside to start work on the replacement of the UK's fleet of four Trident nuclear submarines by 2028.

Defence Secretary Philip Hammond will announce details of the contracts in a written statement to Parliament.

The Conservatives are pressing ahead despite objections from the Lib Dems.

The Tories' coalition colleagues have long argued for a cheaper alternative to replacing the Royal Navy's ageing submarines that carry Britain's nuclear deterrent, and which are due to reach the end of their lives in the next decade.

As part of the coalition agreement, the Conservatives said they would look at alternatives, and delayed a final decision on replacing Trident until after the next election, in 2016.

But in reality the MoD is already pressing ahead with work on the next generation of nuclear armed submarines, says BBC defence correspondent Jonathan Beale.

Mr Hammond will announce details, including the companies which have been asked to do the work, later.

He has also included the final cost of the replacement submarines - expected to be at least £20bn - in his latest budget plans.

The first of the four Trident submarines had been due to leave service in 2022, but the government extended the vessels' lives as part of the 2010 defence and security review.