The plans for discarding EU-derived laws following Brexit have been called “not fit for purpose” by the government’s own independent assessor. Under new legislation that was the brainchild of the former business secretary Jacob Rees-Mogg, thousands of laws copied from the EU to Britain’s statute book will be “sunsetted” by the end of next year if they are not each signed off by ministers to be kept. These include legislation on workers’ rights, such as maximum working time directives and maternity pay, and habitat protections that save endangered animals from development threats. The retained EU law bill (REUL), which threatens up to 4,000 pieces of legislation, has previously been described as “reckless” by legal experts who say it is badly designed and gives unprecedented powers to ministers to personally decide which laws should stay and which should go. The bill has been criticised by legal experts, who have said it gives ministers unprecedented and “undemocratic” powers to make or ditch laws without consultation. Unions, worried it could trigger a wave of deregulation of workers’ rights, say it is a “countdown to disaster”, while the Green party MP Caroline Lucas told MPs the bill was irresponsible and “ideologically driven”. The government’s independent regulation watchdog, the regulatory policy committee (RPC), has looked at the impact assessment for the plans and described it as “not fit for purpose”. “The bill proposes sunsetting more than 2,400 pieces of retained EU legislation (REUL) on 31 December 2023, unless, before then, a departmental review proposes retention of, or changes to, the legislation, or delays the sunset until 2026,” says its report. “No impacts for changes to individual pieces of REUL have been assessed at this stage. We asked the department to commit to assessing the impact of changed and sunsetted legislation, for RPC scrutiny in the future, but the department has not made a firm commitment to do so.” It suggests the government has not addressed the impact of sunsetting these laws on those who will be affected by them, explaining: “As the independent Better Regulation watchdog, it is our view that those affected by regulatory change should reasonably expect the government to properly consider the impacts of such changes. “We are not assured that the impact of changing or sunsetting each piece of REUL will be calculated or understood under proposals currently in place – particularly where no related secondary legislation is required.” The watchdog has also criticised the sunset clause, which gives a deadline for all the laws to be assessed then either amended, discarded or kept. It says the government has not given sufficient reasoning behind the decision to put this deadline in place. The assessment reads: “[The government] must provide a stronger argument for why the sunsetting of REUL is necessary, as opposed to merely setting a deadline to complete the review and change of REUL, including appropriate and robust evidence to support this position.” Alice Hardiman, the RSPB’s head of policy in England, said: “We have been saying for months that the retained EU law bill is not fit for purpose and now the UK government’s own regulatory policy committee is saying the same thing. The far-reaching and devastating environmental implications of this poorly thought through piece of legislation would impact so many areas of our lives that the government should do the decent thing and withdraw it now.” A government spokesperson said: “The regulatory policy committee’s rating of our impact assessment for the retained EU laws bill is disappointing but keeps with ratings of many other enabling bills. Naturally with the immense scope of the freedoms this bill will enable, and the various sectors and departments it involves, it is difficult to quantify impacts in the impact assessment at this time. “The government is committed to taking full advantage of the benefits of Brexit, which is why we are pushing ahead with our retained EU law bill, which will end the special legal status of all retained EU law. This will allow us to ensure our laws and regulations best fit the needs of the country, removing needless bureaucracy in order to support jobs, whilst keeping important protections and safeguards.”