LONDON 

Britain’s Government Security Group has launched an inquiry into a leak from the National Security Council’s discussions about the US using UK military bases in the war with Iran, a letter showed Tuesday.

Cabinet Secretary and Head of the Civil Service Dame Antonia Romeo said an investigation is underway about unauthorized disclosure of proceedings of the National Security Council.

"I can confirm that the Government Security Group is conducting an inquiry into this unauthorized disclosure, which draws on the full range of powers at their disposal," she said.

Romeo confirmed the investigation in a letter to Conservative Party lawmaker Alex Burghart over his question about the proceedings related to the incident.

This came after previous reports suggested that Prime Minister Keir Starmer suggested allowing the US to use the bases to carry out defensive strikes against Iranian targets at the meeting but was met with opposition from some Cabinet members including UK Energy Minister Ed Miliband who led calls to stop the US from using British military bases for its initial action against Iran in early March.

The UK later gave permission to the US to use its bases amid strained ties.

US-Israeli attacks on Iran have so far killed more than 1,200 people, including Supreme Leader Ali Khamenei.

Iran has retaliated with drone and missile strikes targeting Israel, Jordan, Iraq and Gulf countries hosting US military assets.