The former cabinet minister David Davis has pledged to lead a rebellion against the government’s changes to judicial review, calling them a worrying assault on the legal system and attempt to avoid accountability. Before the first major test of the judicial review and courts bill when it is debated in the Commons on Tuesday, Davis wrote in an article for the Guardian that ministers’ plans would “tip scales of law in favour of the powerful”. He cited the power of judicial reviews to give “a voice to victims”, pointing to the overturning of the Parole Board’s decision to release the serial rapist John Worboys. The Haltemprice and Howden MP also praised the campaigner Gina Miller for challenging the government’s position at the start of the Brexit process that article 50 could be triggered without parliamentary authorisation. An overhaul of the judicial review process was promised in the 2019 Conservative manifesto, which said the mechanism should be “available to protect the rights of the individuals against an overbearing state”, but promised it would not be “abused to conduct politics by another means or to create needless delays”. Davis said judicial review “delivers for individuals on matters affecting everyday life” and was constantly being used “to correct fundamental and dangerous errors of law”. “Such attempts to consolidate power are profoundly un-conservative and forget that in a society governed by the rule of law, the government does not always get its way,” he said. Davis also addressed suggestions that so-called Cart judicial reviews could be abolished, which would let the high court review a decision to refuse someone permission to appeal a case. Davis said ministers viewed these as “expensive and unsuccessful”. “While the attack on judicial review, and in particular Cart judicial reviews, is a worrying assault on our legal system, it is only part of the picture,” wrote the former Brexit secretary, whose former chief of staff Dominic Raab is now the justice secretary. Davis said ministers were in effect trying to “deny a court jurisdiction in a certain matter” through a mechanism known as an “ouster” clause. He wrote: “Left unchecked, the use of these ouster clauses could give a government free rein to designate certain decisions it has made, or the use of certain powers it hands itself, to be unchallengeable in the courts. And the government, through this bill, wants to establish a framework for how ouster clauses can be applied to other areas in future legislation. This is entirely wrong. “It all too clearly leaves the door open for further ouster clauses to be created that remove the courts from decisions in matters such as employment tribunals or social security.” Davis said it did “not take a wild imagination to picture a future government, racked by constant losses in the courts on welfare matters, to suddenly legislate to remove the court’s vital oversight functions” in decisions about employment tribunals or benefits. A Ministry of Justice spokesperson said: “This bill delivers on our manifesto commitment to protect the rights of individuals, while ensuring the courts are not open to abuse and delay. “These changes will give the judiciary the power to hold the government to account, while tackling those who look to frustrate the court process.” The MoJ has previously claimed the number of Cart judicial reviews that succeeded was just 0.22%, though Davis queried this in his article, saying the figure was “wildly incorrect” and likely to be “much higher” at about 5.7%.