By widespread accord, Theresa May is the worst Prime Minister in decades. Vacuous statements, confusion over what she wants, vacillation, hesitancy, weakness at every turn – and leadership qualities utterly absent. And the more this continues, the more vehement and numerous the assaults on her position, from inside her party as well as out.

But, in one of those bizarre tricks of politics, could she be on the right track, despite all? What a mess Brexit has become. Close regulatory alignment, but no Customs Union; “three baskets”, but no EU a la carte; a Scottish EU Withdrawal Bill threatening court action and constitutional deadlock; no hard border in Ulster but no soft border acceptable in Brussels; extended transition arrangements sought, but for a short and limited period only, Michel Barnier, the EU’s chief negotiator insists.

And presiding over this, a paralysed, mummified Prime Minister, perched on a threadbare Commons majority close to collapse. On and on and on, day after day, week after week, the maddening Brexit replay loop continues. Is there anyone left who has not been driven to utter distraction by it all?

Theresa May's Brexit strategy involves dividing trade into three baskets with different degrees of compliance with EU rules (Picture: PA)

Ruth Davidson ready to defy UK Government on Brexit

With the legal draft of the EU’s 120-page Draft Brexit Withdrawal agreement published yesterday and a big speech from Mrs May due tomorrow – this week has been hailed as “decisive” – a pivotal, climactic turning point.

But we are inured to such words, for we have heard them for months, only to experience more of the brain-numbing same.

The patience of the British public to leave all this in the safe hands of negotiators is wearing thin. This week Sir Martin Donnelly, the former boss of Liam Fox’s international trade department, likened the exit from the Single Market to swapping a three-course meal for a packet of crisps – taking us right back to the Remain rhetoric of June 2016.

Knives are flashing on all fronts. Within Mrs May’s own party, rebel Remainer Anna Soubry and others have drafted a killer parliamentary motion that, with Labour support, could bring the government down.

In Scotland, a constitutional stand-off has escalated after the SNP administration pushed on with its EU Withdrawal Bill – despite being told it is beyond the Scottish Parliament’s powers. Brexit minister Mike Russell insists the administration will forge ahead with its own legal proposals despite the Presiding Officer declaring it was outwith Holyrood’s competence. It could now go to a court battle between the Scottish and UK governments over a Brexit “power grab”.

But in all of this, how much is the Prime Minister to blame? Is it her unreasonableness? Her stubborn intransigence? In his latest pronouncements this week that will surprise no-one, Michel Barnier insisted once again there could be “no regulatory divergence” from EU rules during the transition and the UK would have to accept the existing body of EU law as a whole.

Did you think the EU citizens’ residence issue had been settled? Think again. He said differences remain over what rights EU citizens coming to the UK during the transition would have and the extent to which the UK would take part in EU-wide justice, foreign affairs and security arrangements.

Did you imagine the Irish border issue had been agreed back in December? And the Brexit departure bill? Apparently not. He said these would need agreement on a legally binding text, including a “common regulatory area” keeping Northern Ireland effectively within the Customs Union.

Little wonder, on the proposal to keep Northern Ireland in the Customs Union, that Mrs May has erupted against what she describes as a breach of the UK’s territorial integrity. And what a precedent would be created for an SNP Government to leap upon and use as a crowbar with which to prise Scotland further apart from the UK?

As for the Brexit departure date, Mr Barnier declared that “there are significant points of disagreement with the UK as to what we understand as the transition agreement, the duration of this, and conditions for such an agreement. The UK would like to, it seems, keep this duration open, which is not possible … In the light of these disagreements, we have not achieved a transition yet.”

And that’s the state of play, no less than 21 months after the UK vote to leave the EU.

So what is it, exactly, that the UK Government is seeking to achieve? Mrs May has sought to reach agreement on how to secure maximum access to the EU’s Single Market without the UK remaining under its legal jurisdiction or paying into an EU budget when we have no say.

The policy of “managed divergence” is based on a “three baskets” strategy. Under this, parts of the economy intimately linked to the EU, including those with complex supply chains such as car manufacturers, would accept EU regulations and a role for EU agencies and the European Court of Justice – a significant blurring of the Prime Minister’s previous “red line”.

In the second basket would be other goods and services – including data and financial services – where the UK would agree common regulatory goals but would have some flexibility to set its own rules. The UK would commit to abiding by European standards on matters such as labour protection, environmental rules, consumer law and competition policy.

The third basket would include areas where there is little or no European law, such as new technology and robotics.

Pragmatic though all this sounds and a fair attempt at compromise, it has already been rejected in Brussels as a workable basis for negotiation. But what is the alternative? Concessions that would keep the UK in the Customs Union would be a continuation of EU membership in all but name, anger 17 million Brexit voters and almost certainly prompt a defeat for the Government. Then what? A UK unable to make its own trade arrangements, and left as a rule taker with no say in EU law and policy? What a travesty. This Prime Minister, for all her faults and all the brickbats, may after all be pushing in the only credible direction.

Bill Jamieson: Theresa May's Brexit strategy is the only credible one