GMB union has called on the government to stop the sale of National Grid’s gas infrastructure.

The comment comes a day after foreign bidders submitted preliminary offers for a majority stake in the grid operator’s gas unit.

National Grid estimates the deal could be worth up to £11 billion.

The union believes National Grid is selling a “key piece of infrastructure, vital to our economy”.

Justin Bowden, GMB National Secretary for energy said: ”Theresa May should intervene and put this sale on hold until the review of the Enterprise Act is completed and there are proper safeguards in place.

“Just days after the government promised to review the Enterprise Act and introduce some long-overdue checks and balances into the sale of our key assets, yet another example comes down the line of fundamental UK infrastructure being flogged off to the highest foreign bidder.”

Earlier this month, Theresa May gave the final go-ahead for the construction of Hinkley Point after reviewing it.

National Grid has refused to make any comment but a spokesperson from BEIS told ELN: “The safety and security of our infrastructure is non-negotiable. There are already robust processes in place to carefully scrutinise investment and ensure the safe operation of our electricity and gas networks.”