A host of senior Conservatives have backed an amendment designed to give MPs greater oversight over the scrapping of thousands of European Union laws.
Downing Street said this week that it was keeping in place the deadline of removing all Brussels-made rules from British statute books by the end of the year.
It has sparked fears that ministers will rip up about 4,000 laws with little oversight from Parliament.
Former Brexit secretary David Davis and fellow former cabinet minister, Sir Robert Buckland, have signed a cross-party amendment calling for more transparency over what will be culled as part of the Retained EU Law (Revocation and Reform) Bill.
The draft legislation is due to be debated in the Commons on Wednesday.
The proposed amendment wants ministers to “publish an exhaustive list of every piece of legislation being revoked” in order to allow the Commons to have the “ultimate say on which legislation is affected”.
Sir Bob Neill, chairman of the Commons Justice Committee, and Caroline Nokes, chair of the Women and Equalities Committee, are also among the prominent Tory MPs backing the change.
Senior Labour MPs giving it their support include former environment secretary Hilary Benn and Stella Creasy, who is leading the amendment.
Ms Creasy, chair of the Labour Movement for Europe group, described the Retained EU Law Bill as a “power grab of epic proportions”.
In a campaign video posted on social media, she said: “Under the cover of Brexit, next Wednesday in Parliament they have tabled legislation that rips up overnight over 4,000 rights that you’ve depended on for generations.
“Like your right to maternity leave or paid holiday, but also your right to compensation if your flight is delayed or your luggage is lost; your right not to have sewage in your water or cancer-causing chemicals in your cosmetics.”
Mr Benn tweeted: “The basic flaw in this shoddy little Bill is that at no time have ministers set out which bits of retained EU law they actually want to amend or to scrap.
“Until they do, it is posturing without a purpose.”
Former justice secretary Sir Robert Buckland told The Times newspaper he understood the Bill would be “an important next stage in terms of clarifying the law and making sure the regulations we need are retained”.
The legislation is designed to make it easier for the UK Government, via Parliament, to amend, repeal and replace EU law retained after Brexit.
It also allows nearly all remaining retained EU law to be either repealed or absorbed into UK domestic law by December 31 2023.
The early signs of Tory discontent come after No 10 was forced to deny suggestions the deadline for removing EU law could slip into next year.
It followed reports that Whitehall departments were gearing up to announce an extension due to how time consuming it was proving to sift through the volume of Brussels-made regulations that need to be replaced.
The Prime Minister’s official spokesman told reporters there were “no plans to change the 2023 sunset deadline” that is written into the Bill.
He said Rishi Sunak wanted EU laws repealed “as quickly as possible” to ensure Britain was run by “our own rules”.
Rocio Concha, director of policy and advocacy at consumer group Which?, said: “Thousands of laws we take for granted, many of them fundamental to how we live our lives — such as product and food safety standards — are affected by this legislation.
“Given the importance of these laws in upholding consumer protections, Which? supports this amendment to provide greater transparency over the process of deciding which laws are to be revoked and giving Parliament powers to challenge its plans.”