LAST week I wrote that Brexit was the biggest voluntary surrender of global influence in history and within days the Irish Brexit border omnishambles proved my point. First the Irish Government and then the DUP demonstrated Westminster’s growing impotence.

It is feasible for different parts of the UK to have different access to the single market and customs union, but that requires some level of border controls and checks, and most vitally: political agreement. Diverging regulatory deals only make sense if your nation is en route to independence, or Irish unification. Nicola Sturgeon and Arlene Foster knew this, and obviously reacted very differently; Theresa May, Sadiq Khan and Carwyn Jones were clearly oblivious to political realities of border politics.

One witty social media comment suggested a compromise where Ireland only has a manned border on Monday, Wednesday, Thursday and Sunday. The really sad thing is it wasn’t the dumbest idea I heard this week.

London Mayor Sadiq Khan called for a special deal for London, which basically demonstrates as loose a grasp on reality as the PM showed in her suggestion to the DUP.

A special deal for London would mean that UK’s capital city was in a different economic area to the rest of the nation it governs over. It would pass regulations for the rest of the UK but not for London and there would be tariffs when goods passed over the M25, which as far as I can tell would be the the most practical place for border controls. It all depends where you draw the London border, of course, but there are about 60 roads into London that would require border controls and half the workforce would have to show their passports on the train every morning.

A Brexit that kept the whole UK in the single market and customs union would still be damaging versus not leaving, and we could live with it economically – but not politically. A soft Brexit would mean maintaining EU regulations; the European Court of Justice being the highest court; freedom of movement to work, for finance and for products would stay; and we would incur a cost well in excess of the £50 billion already suggested. Leavers would say “what was the point of Brexit” and “that isn’t what we voted for”.

So the options are a politically unacceptable soft Brexit, or an economically unacceptable hard Brexit, or cancelling Brexit. Can you imagine the millions of British nationalist Brexit voters accepting the UK admitting to the world that it got it wrong and going cap in hand to the EU asking them to please ignore our strop and please, please, please let us back in, and oh can we please keep all the billions they give us in annual rebates. It won’t happen, and if the UK Government tried, Nigel Farage would be the next PM, or at least Westminster power broker in place of the DUP.

So unless either the DUP decide that Irish unification would be a good thing after all, or everyone who voted leave decides that the most embarrassing national climbdown in political history would put the Great back in Great Britain, we are now heading for a hard Brexit.

This means joining the World Trade Organisation (WTO) to even allow us to trade in the first place and then attempting to negotiate 769 international treaties on trade, airspace, customs, nuclear energy, fisheries and agriculture with 168 non-EU countries plus the EU, all of whom will have the upper hand in the negotiations as the UK will be desperate and on its knees.

Let’s gloss over the fact that there are not enough skilled trade negotiators in the world to make that happen in our lifetimes. This would have massive implications for our democracy and I fear that most people and media commentators have not realised that yet. In order to deliver a hard Brexit, Theresa May must break the UK’s current devolved democratic system because devolution is incompatible with a hard Brexit. This is why the UK Government’s EU (Withdrawal) Bill redirects all the powers back to Westminster and not seamlessly back to the devolved assemblies as we were promised.

FOR example, the UK will ask America for a post-Brexit trade deal, and will be offered the Transatlantic Trade and Investment Partnership (TTIP) on steroids. That will again include access to NHS contracts for big American medical companies. The NHS is devolved to Scotland, so any trade deal involving access to the NHS would currently require the Scottish Government to vote for it and they won’t. Ipso facto, America won’t do a trade deal with the UK if three UK nations controlled by different political parties to the UK Government have a range of vetoes on dozens of trade sectors.

The UK Government just voted down an SNP amendment to allow devolved administrations to amend EU law which directly applies to their nation. The SNP and the Scottish Greens have been calling this a Westminster power grab, which sounds simply like political games being played – but it goes far deeper than that. The Government and the civil servants drafting the EU (Withdrawal) Bill know devolution is incompatible with trade arrangements post-hard Brexit, and as they refuse to vote against it, Labour must know this too.

The trouble with Brexit and borders is that there isn’t a workable solution that maintains the Good Friday agreement, or that can maintain the current devolved democratic system. Devolution must therefore be rewritten to stop devolved parliaments vetoing or delaying trade deals with legal action and also, most likely, to exclude the ability of the Scottish Parliament to hold an independence referendum.

Brexit isn’t just a change in circumstances that justifies a second look at independence – it’s a British nationalist and Westminster centralist coup which needs to subvert Scotland’s democracy by removing and rewriting its hard-won devolved powers.