The government’s pledge to remove up to 4,000 Brussels-related laws faces a “three-year delay”.

A bonfire of EU laws will probably not take place this year as promised, it said last night.

The government has pledged to remove up to 4,000 pieces of Brussels-origin legislation by December after ministers decide which to keep or abandon.

However, the scale of the task is such that Whitehall believes it cannot be completed in time, as thousands of officers would be needed to review the detailed regulations. Some departments want to extend the deadline to 2026.

The delay will hurt Rishi Sunak, who vowed in the summer’s leadership campaign to scrap EU laws in his first 100 days as prime minister (file image).

The Remaining EU Law (Repeal and Reform) Bill is also expected to face stiff opposition when it reaches the House of Lords next month.

A source told The Times: “If the aim is to get all these rules properly reviewed rather than just plugged into UK law then we need more time.

“It’s a completely arbitrary deadline. We will have to make a concession to see it through.”

The likely delay has angered Eurosceptic Tories, anxious for the government to take advantage of Brexit.

It will also hurt Rishi Sunak, who in the summer leadership campaign vowed to abolish EU laws in his first 100 days as prime minister.

Former Business Secretary Jacob Rees-Mogg said: “There is no reason to give in to the unelected remainder in the House of Lords who have consistently sought to thwart Brexit.

“Repealing EU law and replacing it with domestic law seven years after we voted to leave is not particularly ambitious and departments should be prepared to do so.”

The Department for Enterprise, Energy and Industrial Strategy stressed: “The program to review, repeal and reform the retained EU law is underway and there are no plans to change the expiration date for government departments.”