A government move to change state aid rules after Brexit without a vote in parliament is being challenged in court, with a legal campaign group warning the manoeuvre could lead to a similar lack of scrutiny in areas such as workers’ rights and environmental protections. The Good Law Project is seeking a judicial review of the decision to use so-called Henry VIII powers to get rid of EU rules on state aid, which were incorporated into UK legislation after Brexit. The powers, named after the 1539 law which allowed Henry VIII to rule by decree, permit ministers to amend or repeal laws without full scrutiny from parliament using so-called secondary legislation, primarily via something called a statutory instrument. These are normally used to tweak laws because of changing circumstances or gaps, and generally come into force without any parliamentary scrutiny or vote, unless this is specifically sought by MPs or peers. The Good Law Project is challenging the decision of the Department for Business, Energy and Industrial Strategy (BEIS) over its move, under the Brexit withdrawal act, to remove EU state aid rules from British law using a statutory instrument. The legal argument seeking judicial review, seen by the Guardian, argues that the relevant part of the withdrawal act only allows the Henry VIII powers to be used for specific and limited purposes, adding: “It does not permit wide-ranging policy change, including the wholesale abolition of retained EU law.” The 23-page argument says this lack of parliamentary scrutiny “raises an important issue of constitutional law”. The Good Law Project has warned that without proper limiting of the use of such powers, then other EU rules in areas such as employment rights or environmental protections could be removed from UK law without MPs getting a say or a vote. Jolyon Maugham, the barrister who leads the project, said: “Ministers can now rewrite the rules on everything from your rights at work to environmental protections. “It is no exaggeration to state that any area of law previously touched on by the EU is now within the purview of government. Government is wresting power from parliament and giving it carte blanche to ministers to remake almost every aspect of national life.” BEIS is set to oppose the process. In a response to an initial letter notifying the government of the planned legal action, the government legal department said it believed the powers had been used correctly, and that the legal challenge “does not have a realistic prospect of success”. A BEIS spokesperson said the department could not comment on an ongoing legal process, adding: “There will be no reduction in workers’ rights and the new business secretary [Kwasi Kwarteng] has reiterated this multiple times.”