DURING her Indyref launch on Tuesday, Nicola Sturgeon opined that Brexit could have been, if not a roaring success, certainly much less of a burach than it has been. It was Boris wot botched it. “Inadequate planning and thought”, she said, caused the “deep mess” of the Northern Ireland Protocol.

But history may judge that the real culprits were opposition MPs, including the SNP, who failed to moderate Brexit when they had the chance in 2019. Had they voted to remain in the EU single market, like Norway, there need never have been a hard border in the North Sea or any threat to the Good Friday Agreement. Brexit need never caused the current disruption to UK trade.

After the 2016 referendum, there was an overwhelming Remain majority in the Commons, composed of Labour, SNP and anti-Brexit Tory MPs. They had the legislative whip hand.

MPs could have voted to remain in regulatory alignment with the EU using membership of the European Free Trade Area, EFTA, to gain access to the “outer ring” of the EU in the European Economic Area, EEA, along with countries like Norway. Unfortunately, they did not.

Instead, the SNP, along with Labour and Tory Remainers, pursued the undemocratic diversion of a repeat referendum, a so-called “Peoples Vote”, trying to reverse the referendum result.

Nor did the SNP vote for Theresa May’s compromise of regulatory alignment with the single market under the Northern Ireland Backstop. That too could have prevented the incipient trade war with Europe.

Indeed, the fractious British opposition parties rejected all the alternatives to hard Brexit offered to them in successive Commons votes in March 2019. They are collectively responsible for the crisis in Northern Ireland and for the collapse of UK trade with Europe.

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A Norway-style compromise would not have pleased everyone. Hard Brexiteers would have complained that it was “Brexit in name only” , and that Britain was still subject to the laws of the European Court. The EEA is not perfect, but membership would have avoided the chaos and bureaucratic entanglement that has permanently damaged Britain’s image abroad.

Most Brexit voters wanted to restore British sovereignty by leaving the political institutions of Europe. They did not vote to sabotage trade with the wealthiest single market in the world.

The EEA was devised in 1995 as a kind of half-way house for countries who were unsure about full EU membership. Norway liked it so much it stayed put. Britain might have decided, after due consideration, to leave the EEA or even rejoin the EU. All options were open.

Staying in the single market pro tem would have kept free movement, however, and that might have annoyed anti-immigrant populists like Nigel Farage. But Brexit was never about immigration as such. For most voters it was about “taking back control”. This is confirmed by the fact that immigration to the UK has actually increased since 2016 without any popular outcry.

The SNP should realise its own complicity in the Brexit bourach.