In an unusual move, the Energy Secretary – a committed opponent of oil and gas – has told regulators not to approve a new round of drilling that was slated for confirmation in the coming weeks.

It means companies have potentially wasted millions on preparing their bids, with experts warning legal action is likely.

The decision follows crisis meetings held this week between Miliband and his aides after questions were asked by journalists about outstanding drilling applications.

Applications were submitted by 76 oil and gas companies as part of the 33rd offshore oil and gas licensing round initiated by the last government in autumn 2023.

Bids for up to 35 areas of the North Sea were still awaiting a decision from the North Sea Transition Authority (NSTA) when the election was called.

In a statement late on Wednesday, Miliband's spokesman said: “We will not issue new licences to explore new fields, and will not revoke existing oil and gas licences. We will manage existing fields for the entirety of their lifespan.”