Is this the real reason Lord Frost resigned?

In his resignation letter, the Brexit minister Lord Frost justified his decision to quit by pointing to tax rises and Covid restrictions. But there is another potential reason given the timing. Late last week, the UK conceded that the European Court of Justice could have the final say over the Brexit settlement in Northern Ireland.

Frost is a negotiator. It might be that he didn’t want to undermine his successor by over-emphasising the scale of the British retreat. Or it could be that he is holding back dissatisfaction with the negotiations for a second broadside at the Prime Minister.

But it is a critical development. ECJ oversight was always a red line for Brexiteers. Sovereignty demands that the final arbiter of British law resides in the United Kingdom. Where there must be an external mechanism due to an international agreement, there should be an impartial forum that treats both parties equally.