LAST night, Westminster made final our departure from the European Union, not with a bang but a whimper. Actually, the Article 50 debate didn’t even end with a whimper; more an embarrassed shuffle through the lobbies by MPs who knew they were voting for disaster but couldn’t think of anything else to do.

The most important parliamentary debate in half a century, one which will change Britain out of all recognition, was a dismal affair. Apart from Ken Clarke, the SNP and a handful of Labour rebels, Westminster failed to rise to the occasion, let alone hold the Government to account.

You wonder why the Lords of the Supreme Court bothered. They had set out in exquisite detail the rights and responsibilities of Parliament as the apex of the British constitution; the only body with the authority to decide the country’s destiny in Europe. This week, Parliament meekly voted for a four-line Brexit bill, more a tweet than a coherent piece of legislation. The European Union (notification of withdrawal) Bill was an insult to Parliament from a prime minister who still seems to believe she exercises the royal prerogative.

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This was an offer MPs could and should have refused. What self-respecting legislature votes for a measure as important as this before even the White Paper explaining it has been published? The Government held a gun to MPs’ heads: the will of the people and the fury of the tabloid press. But it was a pop gun. MPs should have demanded that they had answers to the fundamental questions about Brexit. What happens about the single market? Will sectors of the economy be exempted? What is the alternative economic strategy?

MPs had to accept the result of the referendum, certainly, but they didn’t have to accept a diktat on the terms of Brexit. To paraphrase Paul Simon, there must be 50 ways to leave the EU, and none was decided or even discussed in this most crucial of debates. MPs rolled over and handed the authority to Theresa May to do whatever she wants. The cliff edge Brexit is all but inevitable; hard Brexit is a certainty.

MPs can try to debate and pass amendments to the Bill in future and the House of Lords has a say but the fateful moment has passed. Parliament only had leverage over Mrs May while they still had their finger on the Brexit trigger. Now it has been fired, they are reduced to spectators in a constitutional process that will be led by Number 10 and the Brexit ministers to a destination they alone will decide.

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The Former Tory Chancellor, Ken Clarke, wasn’t having any of it. He knows that most MPs privately oppose hard Brexit; indeed, any kind of Brexit. Parliament is supposed to be sovereign and MPs are supposed to vote on their consciences. He ridiculed fellow Tories for following the Prime Minister “down the rabbit hole where you emerge in a wonderland where suddenly ... nice men like President Trump and President Erdogan [of Turkey] are just impatient to abandon their normal protectionism”.

To their credit, SNP MPs refused to disappear down this rabbit hole along with Jeremy Corbyn and most Labour MPs. As SNP MP Angus Brendan MacNeil pointed out, after Brexit Britain will be the only country in the Organisation for Economic Co-operation and Development not in a regional trade agreement. We’re leaving the most comprehensive common market in history and joining the half dozen countries in the world isolated from any multilateral trade relationship.

The Government appears to believe that Britain will be given privileged access to the European single market, so that things will remain much the same. But as Sir Ivan Rogers, the former ambassador to the EU, pointed out to a committee hearing yesterday, this is fantasy. The 27 states of the EU cannot possibly endorse such a compromise without undermining the already shaky EU itself. The real argument, he said, will be about how much Britain has to pay to leave: £40 billion to £60bn is the divorce bill.

Britain has long been regarded as a reluctant member of the EU but now we’re being seen as a potential enemy. This is hardly surprising, given the dismissive and often contemptuous terms in which the EU has been described by Brexit MPs, not least by the Foreign Secretary, Boris Johnson. He spent most of his journalistic career demonising Brussels as some kind of petty dictatorship. His confederates in the Commons, Tory MPs Bill Cash and Jacob Rees Mogg, spoke in the debate comparing Brexit to Waterloo and Agincourt, revealing their malign view of the EU as some kind of evil foreign empire. The Article 50 debate was Little England’s finest hour.

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The European Council President, Donald Tusk has spoken of a threat to the existence of the EU. Britain, America and possibly Russia, he believes, seem bent on destroying the EU and reducing Europe to a loose assembly of fractious nations. The disintegration of the EU would not lead “to some mythical, full sovereignty of its member states, but to their real and factual dependence on the great superpowers”.

Mrs May has confirmed the wisdom of those words by her desperate and demeaning attempts to curry favour with the White House and offer a premature and unwarranted state visit to Donald Trump. Britain, it seems, is to find a role as Mr Trump’s pet bulldog, prepared to bark at will to Brussels. These are dangerous times.

Yesterday, you could almost hear the tectonic plates of international relations realigning in a new and dangerous configuration. The Trump administration accused Germany of unfair trading practices by taking advantage of an undervalued euro. Not content with launching a trade war with Mexico, Mr Trump seems intent on taking on the EU itself because the euro is the common currency of all 27 states. He has already threatened to slap punitive duties on German cars.

Yet, for half a century, America regarded European integration, and British membership of the EU, as the key to Western security and economic cooperation.

Brexit will hugely damaging to the Scottish economy, which has benefitted from inward migration, subsidies and trading privileges from the EU. But more than that, Scotland finds itself standing in appalled disbelief at the way in which the UK is being sold on the cheap to Mr Trump, a president so irrational and impetuous that he seems unlikely to last until the mid-term elections let alone 2020.

Under Mrs May, Scotland has become an accessory to destructive acts of economic nationalism that threaten not only Britain’s economic wellbeing but also the stability of Europe and the world. It was hard to disagree with the exasperated Mr MacNeil, yesterday when he said that “sometimes the House of Commons simply takes leave of its senses”. I’m afraid politics in general has simply stopped making sense.