British businesses need to tell the Government to leave EU law alone, the incoming head of the TUC has said.

Paul Nowak said “scrapping employment laws” inherited from the EU would not be in the top 10 priorities for “most serious businesses in the UK” and company bosses should be “unafraid” in telling the Government so.

His comments come a day after a committee of MPs began debating the Government’s Retained EU Law Bill, which opponents fear will weaken protection for workers.

Most serious businesses in the UK are not interested in scrapping the Working Time Directive and getting rid of people’s rights to paid holiday

Mr Nowak, who takes over as general secretary of the TUC in January, told a meeting organised by Labour in Communications on Wednesday that businesses had to “raise their voices”.

He said: “Most serious businesses in the UK are not interested in scrapping the Working Time Directive and getting rid of people’s rights to paid holiday.

“There’ll be some who would love it, but most businesses, if you asked them, rank your top 10 list of things that would help your business grow and create a better environment in which your business can operate, scrapping employment laws, making it harder for workers to take strike action wouldn’t feature in the top 10.

“It features in the top 10 of people like the policy wonks in Downing Street and the people in the right-wing think tanks who manage to get themselves into special adviser positions, but I think businesses need to be saying to Government ‘leave this stuff alone’,”

The Bill, introduced by then-Business Secretary Jacob Rees-Mogg, would make it easier for the Government to repeal more than 2,000 laws derived from the EU by scrapping any that were not actively incorporated into UK law by the end of 2023.

Mr Nowak also warned that the Government would try to make it harder to strike in other sectors if its plans to ensure minimum service levels during rail strikes were successful.

He said: “Without a doubt, this is going to be the thin end of the wedge, isn’t it?

“If the Tories can get away with it in rail and parts of transport, it will be a model they will roll out to other parts of the economy.”

He added that the TUC would take the Government to court and ensure the Conservatives paid “a high political price” if the proposals became law.

Asked about the TUC’s relationship with the Labour Party, Mr Nowak said that while there would always be “tensions”, the relationship was “good”.

He said: “Finding a way for Labour and the unions to work together in a grown-up way is going to be really important.”

Referring to the row over whether Labour frontbenchers should stand on picket lines, he said: “I don’t think you want to distil the relationship between unions and the Labour Party down to whether a frontbencher turns up and has a selfie with somebody on a picket line.

“I’ve been involved in lots of strikes. None of them have been won because a member of the shadow cabinet turned up and had their photograph taken.

“And I do think Keir (Starmer) is right in that Labour and the unions have different jobs to do.”