‘The [British] public has voted and I do think it’s seriously disrespectful and politically utterly counterproductive to say ‘sorry guys, you’ve got it wrong, we’re going to try again’.” So said Vince Cable in September 2016. Since then, though, Cable has become Liberal Democrat leader. Now he’s pushing hard for a second referendum on European Union (EU) membership.

Last week, Cable’s party tried passing a Commons amendment to hold a referendum on the final Brexit agreement in December 2018, vowing to campaign to stay in. The Liberal Democrats, it seems, aren’t democrats at all. And they’re only ‘’liberal’’ until the electorate makes a decision they oppose.

Despite recent progress in negotiations, the campaign to reverse Brexit is still gathering pace. Run by ultra-Remain MPs and peers, it’s backed by big corporations which, benefiting from the status quo, are determined to maintain it. After pious claims about “respecting the referendum”, some now openly admit they want to upend the biggest vote in British history. “First step towards defeating Brexit,” tweeted Lord Adonis after the Government’s recent Commons defeat.

These Brexit negotiations are tough. The self-serving Brussels bureaucracy is making it difficult for Britain to leave — to discourage others. But rocky departure talks don’t justify ignoring a “once in a generation” vote, won by a margin of 1.3 million people. “This is your decision,” said the Cameron government’s outrageously pro-Remain mailshot, sent to every UK household ahead of the June 2016 vote. “The government will implement what you decide.”

In 2015, parliament had voted by six-to-one to give the people the decision on the United Kingdom’s EU membership. After the referendum, in February 2017, parliament voted again, overwhelmingly, to implement Article 50. In the June general election, the Conservatives and Labour both stood on a platform to leave the EU, including the single market and customs union. Between them, they won over 80 per cent of all votes. The two parties calling for a second referendum, the Liberal Democrats and Scottish Nationalists, both saw their vote share fall.

But the Tories’ fragile Commons majority has energised those determined to reverse Brexit. Labour’s policy constantly changes, and currently amounts to doing or saying anything necessary to topple the Government. Last week, deputy leader Tom Watson argued for a second referendum, just as Diane Abbott ruled it out. Amid such chaos, some Remainers sense an opportunity. The scarier Brexit is made to look — the difficulties constantly exaggerated, the potential economic gains utterly ignored — the greater the chances the public can be railroaded into voting again. Then, with much of the political and media establishment on side, and masses of campaign cash, Brexit can be blocked.

A second Brexit referendum, though, would be an economic and political disaster. If agreed, the UK’s Article 50 negotiations would be destroyed. The EU would have every incentive to offer the worst deal imaginable — ensuring the terms are rejected by the electorate, with Britain (and our money) then staying, exactly as Brussels wants.

If, in contrast, the UK commits to leaving the single market and customs union with no question of a second referendum, there is a huge incentive for EU governments to strike agreeable trade terms, given the value of British markets to their exporters. The prospect of a second referendum would also seriously prolong business uncertainty, harming investment and jobs. If voters reject “the deal”, would there be another negotiation and yet another referendum? The best of three, or five? Our political system would become paralysed by splits, confusion and rancour. The ongoing uncertainty and instability would impact on financial markets, hitting sterling, equities and the broader business environment.

And if Brexit is reversed, our subsequent EU membership would surely be on far worse terms — with no rebate and perhaps no opt-out from the dysfunctional single currency. What do the Brexit-blockers say about recent renewed calls from Germany’s Martin Schultz, now on course to share power with German Chancellor Angela Merkel, for “a United States of Europe”?

Be in no doubt, the drumbeat for a second EU referendum is getting louder. Former British prime minister Tony Blair is on manoeuvres, as is Cable’s predecessor Nick Clegg — who, since he lost his Commons seat last June, seems to be given more television airtime than ever. Early in 2018, ultra-Remainers in the Lords will do their utmost to thwart Brexit.

Those agitating for a second referendum must be called out, their arguments exposed as disastrous and anti-democratic. And ministers need to move the conversation on from the process of leaving to the outcome itself — presenting Brexit as what it is, an opportunity for national economic renewal.

— The Telegraph Group Limited, London, 2017

Liam Halligan is a British economist, journalist and broadcaster.