Brexiteers, stop twitching! Ever since the High Court ruled that the Government cannot start the Brexit negotiations without having a vote in Parliament, a succession of curtain-twitching conspiracy theorists have been up in arms.

Ukip’s Nigel Farage predicted that there would be unrest on the streets against an establishment stitch-up. Michael Gove shrieked in the House of Commons yesterday that the will of the people is being thwarted. David Davis spluttered that Lloyd-George would be spinning in his grave if peers were allowed to stand in the way of the people.

The favoured plot in the fevered imaginations of these over-excitable Brexiteers — egged on by splenetic headlines in the Right-wing press — is that Lib-Dem peers in the House of Lords are planning to vote en masse against Article 50.

So let me provide some reassurance: Lib-Dem peers are as aware as anyone of the limits of what an unelected chamber can do. They are not out to subvert democracy. There is no perfidious plot incubating on the red benches.

Furthermore, regardless of the views of Lib-Dem or SNP MPs, there isn’t the remotest chance that the Commons is going to block the Government’s triggering of Article 50 since the Labour Party has already stated that it will vote with the Government.

So why, then, are the Brexiteers in such a febrile state, looking under every mattress in Westminster for the next pro-European plot? Why have these erstwhile advocates of the rights of the Mother of All Parliaments become such supine apologists for the power of the executive over the legislature? I thought they wanted MPs to “take back control”?

The reason stems from the dishonesty with which they won the referendum in the first place — deliberately withholding what Brexit actually means in practice from voters. It’s now coming back to haunt them. The truth is that many Brexiteers knew what they were against — the EU — but appear to have little idea of what they are actually for. Now that they’ve won they hate the responsibility that comes with victory. That is why they continue to parrot slogans or focus on easy pickings such as the colour of our passports.

But they know in their hearts that at some point they must move beyond slogans, beyond the colour of our passports and provide answers to complex dilemmas. And when those crucial choices are made — are we in or out of the customs union? In or out of the single market? In or out of EU crime-busting organisations? — Parliament has every right to make itself heard.

'They know at some point they must move beyond slogans and give answers to some complex dilemmas' Nick Clegg

That is why Lib-Dem MPs will work across party lines in the Commons to amend any Article 50 legislation to ensure that we provide sensible, economically rational answers to those questions and give the people a say in the final deal which eventually transpires in years to come.

The Government has a mandate to pull the UK out of the EU. It has no mandate on how to do so. Parliament has every right to be involved at the outset — and the people have a right to have their say at the end.

So it’s Parliament and the people versus the Brexit establishment. Now that’s what I call a role reversal. No wonder the Brexiteers are getting so twitchy.