Three new Royal Navy patrol vessels will be built on the Clyde under a £348 million contract which will secure over 800 jobs, the Ministry of Defence has announced.

The vessels, which will be used by the Royal Navy to support the UK interests at home and abroad, will be built at BAE Systems' shipyards.

Defence Secretary Michael Fallon said : "UK warships are only built in UK shipyards.

"This multimillion-pound contract shows our commitment to investing in new ships for the Royal Navy and maintaining in the UK the expertise needed to build the warships of the future.

"It will benefit the dedicated workers of the Clyde, their families and the local economy in Glasgow.

"This sort of investment by the UK Government is vital for the sustainment of shipbuilding in the city and the hundreds of specialist manufacturing and engineering roles that play an important role in providing war fighting capability for the Royal Navy."

The MoD declined to comment on whether a Yes vote in the independence referendum would have any bearing on the contract.

"The Government is not planning for independence and is not making any contingency plans," a spokeswoman said.

Featuring a redesigned flight deck to operate the latest Merlin helicopters as well as increased storage and accommodation facilities, the offshore patrol vessels (OPVs) build on the capability of the Royal Navy's current River Class vessels.

Chief Secretary to the Treasury Danny Alexander will today visit the BAE Systems site alongside Defence Equipment Minister Philip Dunne to meet some of the employees who will be involved in manufacturing the vessels when work begins this autumn.

Mr Alexander said: "I am delighted that we will be building the Royal Navy's new offshore patrol vessels in Glasgow.

"Today's announcement continues over 200 years of tradition building the nation's leading ships on the Clyde. This will also support hundreds of jobs in the region and make an important contribution to the wider UK economy."

Having played a role in the construction of HMS Queen Elizabeth, workers on the Clyde are now manufacturing blocks for the second aircraft carrier, the Prince of Wales, which is being assembled in Rosyth dockyard, near Edinburgh.

The first OPV is expected to be handed over to the Royal Navy in 2017.

Mick Ord, managing director at BAE Systems Naval Ships, said: "This is a significant contract award which marks the beginning of a new and exciting chapter for the UK shipbuilding sector.

"We're making major investments in our people, technology and facilities to create a world-class complex warship capability and the OPVs provide an opportunity to embed these new ways of working.

"This will ensure we remain competitive and are best placed to secure the Type 26 manufacturing contract, which together with the investments will sustain the long-term future of this highly skilled industry."