London-listed blue-chip companies, BAE systems and Rolls-Royce, have received the contracts, the MoD said in a statement, adding that the investment was part of a planned 10-billion-pound spend for the whole delivery phase.

"The Dreadnought Class will be crucial to maintaining and safeguarding our national security, with the nuclear deterrent protecting every UK citizen from the most extreme threats, every minute of every day," defence procurement minister Jeremy Quin said.

(Reporting by Muvija M; editing by William James)