Brexit means Brexit. Article 50 is irrevocable. There can be no turning back. Our car is headed for the cliff-edge, and the brake lines have been cut. That is what the Brexit extremists want us to believe. But they are wrong. Legally, practically and democratically they are wrong.

Let’s start with the legal argument. Since article 50 was triggered back in March, starting the two-year countdown to Brexit, government ministers have gone out of their way to give the impression that the notification cannot be withdrawn. Indeed, the minister of state at the Department for Exiting the EU, Lord Callanan, recently had to apologise twice to the House of Lords for wrongly claiming that the UK Supreme Court had ruled article 50 to be legally irrevocable. In fact, the Supreme Court ruled nothing of the sort. But you don’t just need to take my word for it: Lord Kerr, the man who helped write article 50, made it clear during a speech organised by the Open Britain campaign that the notification represents nothing more than the current government’s intention to withdraw. Intentions can be changed, and Lord Kerr was crystal clear that there is no legal barrier to withdrawing article 50.

Sir Konrad Schiemann, formerly the UK’s judge at the European Court of Justice, told a parliamentary committee recently that “the probability is that it [article 50] can be withdrawn.”

So legally, there is no doubt that our article 50 notification can be withdrawn. And how about practically? Would the other EU member states welcome such a decision? Well, we know the answer to that as well. They would be delighted. Again, don’t take my word for it, listen to what European leaders themselves are saying.

Donald Tusk, president of the European Council, has said “it is in fact up to London how this will end: With a good deal, no deal or no Brexit”. Leo Varadkar, Ireland’s Taoiseach, has said “Well, I still hope that [Brexit] won’t happen”. The French president, Emmanuel Macron, says “the door remains open” for Britain to change its mind about Brexit.

In a world facing numerous threats, from Russia to terrorism, from climate change to nuclear proliferation, we all need the added complications of Brexit like we need a hole in the head. And let’s not forget how welcomed it would be across the Irish Sea.

But what about democratically? The hard Brexiters love hiding behind the vague and dangerous phrase “the will of the people”, as if everyone in this country is in total unity about Brexit.

Well, I don’t know about you, but with my family and friends we often struggle to even agree on what bar or restaurant to go to, let alone the future direction of the whole country. So the idea that there’s some kind of monolithic National Will that wants to pull us off the Brexit cliff-edge is ludicrous.

Brexit is a fiendishly complex process that will affect our lives and the lives of future generations for decades to come. It is the single biggest national act of self-harm in our history. Every day, new facts come to light that people couldn’t possibly have known during the referendum. The idea that we only have one course of action that we must follow, no matter what new information we learn, and that none of us have the power to change it, is an affront to democratic principles.

If you order a meal, and yet what comes out of the kitchen is something completely different and much worse, then it’s your right as a paying customer to send the food back. When the facts change we should have the space to think about changing our minds.

Millions of people who voted Leave were told that Brexit would mean more money for the NHS (but all we got was £3bn extra for government preparations to leave the EU in the Budget), control of our laws and more prosperity for everyone. What’s on offer instead is less money for the NHS, a government that is trying to side-line and ignore our democratically-elected parliament, and everyone in this country being worse-off.

If what we have been promised turns out not to be what’s on offer, we have the right to change our minds. Whatever happens in the coming months don’t let anyone tell you that article 50 can’t be revoked legally, practically, or democratically.

Ian Murray is MP for Edinburgh South and a leading supporter of Open Britain.