LONDON (Reuters) - Britain's ministry of defense said on Saturday that construction work will begin on the country's new nuclear submarines, announcing nearly 1.3 billion pounds ($1.7 billion) of new investment with defense firm BAE Systems.

Lawmakers backed renewing Britain's ageing nuclear weapons system earlier this year, a multi-billion pound project regarded as key to maintaining the country's status as a world power following its vote to leave the European Union.

"The investment will support delivery of the Government’s commitment to retain the Trident-based continuous at sea deterrent – the ultimate guarantee of our safety – and build the new fleet of four Successor Ballistic Missile submarines," the defense ministry said in a statement.

BAE Systems said the first new submarine will enter service in the early 2030s.

(Reporting by Costas Pitas; Editing by Alexander Smith)