SHIPBUILDERS union GMB has accused the UK Government of “undermining the national interest” by allowing overseas companies to bid on major contracts.

Jude Brimble, the union’s national secretary, said ministers are giving away “the key to unlocking the country’s massive shipbuilding potential” by giving foreign firms the chance to build three 40,000 tonne vessels.

The craft are planned for the Royal Fleet Auxiliary (RFA), which supports the Royal Navy. In September the union called for clarity over how contracts for these vessels will be awarded.

Now it is calling for cross-party action after the Ministry of Defence confirmed the business may go to overseas yards instead of UK facilities.

The confirmation came from Harriett Baldwin, the Under Secretary of State for Defence Procurement, after Glasgow South West MP Chris Stephens lodged an official question with House of Commons authorities.

Responding, Baldwin said: “Warship build will be via competition between UK shipyards.

“All other naval ships should be subject to open competition, provided that there are no compelling national security reasons to constrain a particular procurement to national providers.

“Integration of sensitive UK-specific systems will be done in the UK, where possible.”

The decision comes despite the recommendations of the Parker Report, which aims to aid a “renaissance” in the sector and informed the National Shipbuilding Strategy unveiled by then defence secretary Michael Fallon two months ago.

John Parker, a former shipbuilding executive, argued for a “modular” approach to construction to benefit more sites.

Brimble claims the failure to adopt this approach for the RFA orders is a “tragic missed opportunity”. She said: “Against the backdrop of Brexit, the government should be fighting for the defence and growth of as much decent work as possible, not hiving off huge skilled manufacturing opportunities to international competitors for the lowest cost possible.

“The RFA vessels will support and serve our Royal Navy and we have the capacity and skills base to deliver their manufacture, while generating hundreds of millions of pounds worth of wages for the UK economy. It beggars belief that the government wants to give this golden opportunity away.

“Instead of undermining the national interest, the government should be defending our vital shipbuilding industry.

“It can start doing this by ensuring that in future all Royal Navy and Royal Fleet Auxiliary vessels should be built by UK shipyards.”