A constitution is the legal soul of a nation. It distills its values through a system of government, a vision of society and, most importantly, by setting down the rights of every citizen. For this reason, constitutions should be deliberated upon, negotiated and sometimes even fought over – they must not be imposed from above. That is what makes the UK’s current trajectory so troubling.

The coming debate over the British constitution, with human rights, judicial review and the independence of the judiciary on the agenda, is a purely Conservative Party affair. It will be a fight between illiberal ideologues and an increasingly weak group of “Runnymede Tories”, classic Tory liberals in the mould of David Maxwell-Fyfe, the Conservative home secretary who drafted the European Convention on Human Rights (though minus his homophobia).

The appointment of Conservative Brexiteer Suella Braverman as Attorney General, the government’s senior legal officer, is the opening salvo from the ideologues. With a majority of 80 seats, there is no need for Boris Johnson to worry about cross-party, or even inter-party, consensus. So for non-Tories, constitutional reform is about to become a spectator sport and there isn’t much we can do about it. But it does help to anticipate the government’s direction and Braverman’s appointment provides a good clue.

Before we get there, it is important to understand that plans to weaken human rights protections and judicial oversight have been a long-term Conservative project, as I have explained in detail elsewhere. Almost 15 years ago, David Cameron promised to replace the Human Rights Act with a “bill of rights” (even though, arguably, that is exactly what the Human Rights Act is). Since then there have been a number of false starts.

The 2012 Bill of Rights Commission was a compromise necessitated by the Conservative-Liberal Democrat coalition, comprising four Conservatives and four Liberal Democrats – a kind of constitutional Brady Bunch. It reached a predictably messy conclusion, with a majority recommending a bill of rights, but essentially for cosmetic reasons. Two Conservatives argued that real change would only be achieved if the UK withdrew from the European Convention on Human Rights (ECHR), two Liberal Democrats said that unless such changes were intended to strengthen the Human Rights Act, they should be rejected.

After the 2013 commission, the Tory ideologues were in the ascendency, their high point being justice secretary Chris Grayling’s 2014 plan, “Protecting Human Rights in the UK”, a name which would have made Orwell blush. It called for significant weakening of the Human Rights Act and a medium-term plan to withdraw the UK from the ECHR. Dominic Grieve, the then attorney general and a true liberal Tory in the Maxwell-Fyfe mould, lost his job over his opposition to the plan.

When David Cameron won a small Conservative majority in 2015, it appeared the manifesto promise to replace the Human Rights Act, along the lines of the Grayling plan, would be delivered. Theresa May, as home secretary, was one of the most vociferous critics of the Human Rights Act and the ECHR, which she openly said the UK should leave. But it was Michael Gove who was appointed to the task and who envisaged replacing European law with “Commonwealth law”. But he was sacked as justice secretary before he could complete the project. Brexit, and the loss of the Conservatives’ majority at the 2017 election, once more put the plans on ice.

The Conservatives’ 2019 manifesto was strangely vague on the subject (compared to previous grand promises to repeal the Human Rights Act), pledging only to “update the Human Rights Act and administrative law to ensure that there is a proper balance between the rights of individuals, our vital national security and effective government”, and to prevent judicial review being “abused to conduct politics by another means”. This would be achieved through another commission, on “Constitution, Democracy & Rights”, though this time without the pesky Liberal Democrats.

Now, unconstrained by tight parliamentary arithmetic or a coalition government, Johnson has a large majority to do essentially what he wants. The so-called Runnymede Tories, such as Grieve and former justice secretary David Gauke have left the building, or, more accurately, been forcibly escorted out. The only remaining question is which strand of constitutional thinking will prevail.

Which brings us back to Braverman, a former junior barrister with unambiguous views on what needs to be done. She is the opposite of Grieve, and that is plainly deliberate. A former European Research Group vice-chair and an ardent Brexiteer, she has written that “repatriated powers from the EU will mean precious little if our courts continue to act as political decision-maker, pronouncing on what the law ought to be and supplanting parliament”. We must “take back control,” she wrote in an article which reads like a cover letter for the attorney general post, “not just from the EU, but from the judiciary”. She is a human rights sceptic, believing that they have been taken too far by activist judges both here and at the European Court of Human Rights. She has said the human rights “mission has failed” and that the “cult of the individual” should be tempered by restricting rights to those who have fulfilled their social responsibilities, reflecting a long-standing demand of the religious right.

As demonstrated by the treatment of Sajid Javid in the reshuffle, Johnson and his adviser Dominic Cummings, who has said that after Brexit “we’ll be coming for the ECHR…and we’ll win that by more than 52-48…”, have no qualms in replacing potential dissenters with ideological fellow-travellers.

The appointment of Braverman shows that Johnson does not want a Grieve-like independent thinker as Attorney General. It also leaves no room for doubt over the ideological direction of travel, which will be to reduce human rights protections and the means of holding government accountable through the courts. With the executive now essentially free to do as it wishes, the timing of this constitutional soul-searching could not be more dangerous.