LONDON, March 13 (Reuters) - Britain is to award firms millions of pounds worth of contracts for its submarine fleet, bringing it a step closer to the costly and controversial renewal of its Trident nuclear deterrent, an issue which has divided its coalition government.
The country has been locked in debate over the merits of replacing the vessels carrying the deterrent - which currently consists of four ageing Vanguard-class submarines carrying Trident missiles - which would cost 20 billion pounds ($33 billion) at a time when the cash-strapped government is trying to cut back on spending.
The Conservative party, the senior member of the two-party ruling coalition, favours a like-for-like replacement of the deterrent while its junior Liberal Democrat partner believes the current size of the fleet is more suited for the Cold War era and should be scaled down.
Defence Secretary Philip Hammond, a Conservative, will unveil the contracts on Thursday on a visit to defence contractor BAE Systems' historic Barrow-in-Furness shipyard on England's northwest coast, which has been building submarines for over 120 years.
Sources familiar with the matter said the deals will be for the Successor submarine to replace the Vanguard as well as the Astute-class attack submarine programme. The MoD is set to start sea trials early next year for the third of seven planned Astute-class nuclear powered ships built at the Barrow yard at a cost of more than 1 billion pounds each.
Renewing and maintaining Britain's overall submarine fleet is expected to cost 38 billion pounds over the next decade, representing a large share of the country's 164 billion pound defence equipment budget, the defence ministry said last month.
While a final decision on Trident renewal is not expected until 2016, a year after the next parliamentary election, Hammond's announcement will likely be seen as a reinforcement of the Conservatives' commitment to the like-for-like replacement option.
Since 2011, the government has already spent 730 million pounds on assessing the Successor programme, it said last December.
Britain estimates the Successor programme alone could employ up to 6,000 people over the course of its building programme and provide over 850 British companies such as BAE, Rolls Royce and Babcock with work.