Britain’s Ministry of Defence (MoD) has awarded contracts valued at £350 million ($552 million) to U.K. companies for the design of nuclear-deterrent submarines to be built in the future.

MoD said the first of the next-generation Successor submarines is to be delivered in 2028, replacing the current Vanguard Class submarines that carry the UK's Trident nuclear deterrent.

Britain’s current fleet of nuclear submarines comprises four vessels.

This government is committed to maintaining a continuous submarine-based nuclear deterrent,” Defence Secretary Philip Hammond said Tuesday.

“The contracts announced today … symbolize an important step towards renewing our nation's nuclear deterrent into the 2060s… By making the core equipment program fully funded and affordable, we are able to confirm additional equipment projects which help safeguard our national security.

The contracts are part of a £3 billion ($4.7 billion) design program that MoD unveiled in May.

The ultimate cost of the replacement submarines is expected to amount to at least £20 billion ($31.5 billion).

The ministry said the three British companies were given the contracts -- BAE Systems, Babcock International Group and Rolls-Royce -- are expected to create at least 1,900 jobs from the deal.

The bulk of the contracts – valued at £328 million ($517 million) – was granted to BAE Systems Maritime–Submarines, which will be responsible for the overall submarine design.

The BBC reported that the Liberal Democrats object to this massive expenditure given the budget cuts the country has imposed in other areas, while their coalition partners, the Conservatives, endorse the program.

A decision on the final design and building of the new submarines will not be made until 2016, as the Tories may still opt for cheaper alternatives in replacing the Trident fleet.