Might it be that David Frost sees the prospect looming of a deal on Ireland that Brexiteer comrades may portray as capitulation, and has decided to put himself at a safe distance from any backlash? The former British chief negotiator may reason that his departure at this point will mean that history, and the backbench Tories he courts, will judge him more kindly.
There is some reason to believe that the UK may indeed be softening its hardline stance on the Northern Ireland protocol. Eased by Brussels' decision to facilitate the export of medicines to the North, bypassing single market rules, the UK has let it be known that it would be prepared to park its objections to a role for the Court of Justice of the European Union (CJEU) in interpreting EU rules in the North. Park, that is, until sometime in the future when the UK and EU regulatory regimes actually begin to diverge.
Frost's resignation letter only suggests any kind of Brexit nuance in its reference to moving 'as fast as possible to where we need to get to'
And then the EU-UK negotiations were themselves parked for the Christmas break and Frost’s resignation was leaked and formalised.
With Brexit and protocol policy very firmly driven by British prime minister Boris Johnson, with whom Frost appears to have marched in lockstep, there is no evidence that the latter's resignation reflects any opposition to the CJEU move, to the toning down of threats to use the nuclear article 16 repudiation option, or to friendlier hints that European Commission attempts to ease rules on Irish Sea checks may make a deal possible. Frost's resignation letter only suggests any kind of Brexit nuance in its reference to moving "as fast as possible to where we need to get to: a lightly regulated, low-tax, entrepreneurial economy, at the cutting edge of modern science and economic change". That is a clear nod to the extreme Brexiteer libertarians in the Tory party whose agenda of deregulation and free market boosterism has fanned a distrust of what they see as Johnson backsliding.
Truss, who has strong support in the free market right of the party, will be wary, like Johnson, of being seen to concede too easily
Cautious continuity on Brexit policy is likely, with a deal in the spring by no means certain. Frost's successor, foreign secretary Liz Truss, a former trade secretary who is said to want Johnson's job, now joins the long line of UK Brexit negotiators – David Davis, Olly Robbins, Dominic Raab, Steve Barclay, Michael Gove – none of whom saw leadership ambitions enhanced in the difficult role. Truss, who has strong support in the free market right of the party, will be wary, like Johnson, of being seen to concede too easily, and may prefer to stall for time.
That could be done by avoiding a full breakdown of talks or repudiation of the protocol, which could lead to a trade war with frustrated EU member states. The end game of this particular saga remains unknowable. It continues to remain hostage to the internal dynamics of a Tory Party in crisis.