Last week was not a good week for the government. On Thursday the high court ruled that the prime minister was acting unlawfully in seeking to use prerogative powers to invoke article 50, and reminded her that only parliament can make or repeal laws. The court also reminded Theresa May that when it comes to legislation, parliament is sovereign.

Then on Friday, Stephen Phillips – a Conservative MP and a leave campaigner – resigned, citing “irreconcilable differences” with the prime minister’s approach to Brexit, in particular her desire to sideline parliament and avoid scrutiny. So much for building a national consensus on Brexit.

This matters because the decisions to be taken in the coming months and years on the UK’s future relationship with the EU are the most important for a generation. That is why they need to be properly considered and debated. As Labour has repeatedly argued, that means the government putting before parliament the basic terms it wants to achieve from Brexit negotiations.

Yet after another statement from Brexit secretary David Davis on Monday, we are none the wiser about what the government’s approach will be or the basic terms it will seek to achieve. We still do not know the government’s stance on the single market, on the customs union, or on cooperation with our EU partners in combating serious crime and terrorism. We do not know if the government has a plan for transitional arrangements in March 2019, or if special consideration will be given to the situations in Northern Ireland, Scotland and Wales. We don’t even know how the government will proceed if the supreme court upholds the high court’s ruling.

Of course, the government should not reveal the detail of its negotiating hand or provide a running commentary. But these are basic questions, and they deserve clear answers. Instead, ministers have approached this crucial task in entirely the wrong way, sowing discord where there could be harmony.

In the last week that approach has further unravelled, and in a particularly ugly way.

In the aftermath of the high court judgment, there have been appalling personal attacks on the judges involved and the judiciary in general, including the suggestion that they are “enemies of the people”. Having worked in countries where judges do as the executive tells them, I know how corrosive this can be. The independence of the judiciary should be a prized part of our democracy, not something to be threatened when the governing party disagrees with a verdict.

Our judges were asked one simple question last week: is the prime minister acting lawfully? Having listened to argument from both sides, they concluded that she was not. They upheld the law and protected parliamentary sovereignty.

Robust comment on and criticism of court judgments is right in a country that respects free speech. But we all have a duty to stand up for the rule of law and the independence of the judiciary. Many people, myself included, think the lord chancellor has been far too slow and too reluctant to do so.

The one aspect of Davis’s statement that was clear was that ministers intend to appeal the high court’s ruling to the supreme court. They are, of course, perfectly entitled to do so. But would it not be better for the government to stand back and ask whether the national interest is really served by spending the next month fighting a high court ruling, while providing no further clarity or accountability on the basic terms of Brexit?

The government, however, seems determined to carry on down the same path, adamantly insisting that the executive alone should have the right to trigger our exit from the EU. I have repeatedly made it clear that Labour accepts and respects the outcome of the referendum: there is a mandate to leave and Labour will not frustrate it by voting down article 50. But there is no mandate for the terms upon which we exit, and the stakes are too high for the prime minister to decide this by herself.

That is why the government should come clean and put the basic terms of its Brexit plan before the Commons, allowing scrutiny, transparency and challenge. Those are – along with judicial independence – central tenets of our democracy. They are also far more likely to lead to the right outcome for all of us and for generations to come.