In between Cameron’s resignation, May’s honeymoon period and the shock General Election – a hardcore group of undemocratic, angry, hostile remainers, from all wings of British politics, have pounced on government instability, mobilised and grown in strength.

Their aim? To stop Brexit and to reverse the decision made by 17.4million people 18 months ago.

Lord Digby Jones calls them the ‘ABC club’ (Adonis, Blair, Clegg). But this group spreads its net wider. They are ultra-remainers with an A-team consisting of Chuka Umunna, Anna Soubry, Nicky Morgan, Ken Clarke, Vince Cable, Nicola Sturgeon and Gina Miller – all joined in arms with organisations such as the CBI, the TUC and Open Britain to name but a few.

They are all united in their aim of stopping Brexit. They continually seek to undermine the government on its Brexit strategy and weakening our influence around the negotiating table. Lord Adonis and Tony Blair both want a third referendum to reverse the leave vote; Nicky Morgan and Anna Soubry both persistently call for Britain to stay in the Single Market; and the CBI called for Britain to say in the Customs Union on Monday.

The Brexit betrayal is happening in front of our very eyes.

I don’t think any of us, as Brexiteers, could have anticipated what was to come. Were we caught off-guard, amidst our jubilation of a Leave victory? Yes, I think we were.

Their determination is matched only in their organisation. These ultra-remainers are highly motivated and highly coordinated in their efforts, particularly in their approach to securing media coverage for their arguments.

In Brussels, their efforts are celebrated, particularly in the EU parliament. Guy Verhofstadt smiles with glee every time they chirp up. Why? Because they are doing their dirty work for them while they stay on message. It’s divide and conquer. As the ultra-remainers undermine our own government, the EU smells weakness and draws strength from it.

I’ve called for these people to back Britain. If we work together, we will come out of Brussels with a better deal. But this is not going to happen.

Therefore, Brexiteers need to unite. It’s now or never. A new year, a new stage of negotiations in Brussels. By uniting, with one voice, we will ensure to hold the government’s feet to the fire on delivering a Brexit which is representative of what millions voted for.

Leave Means Leave, Labour Leave, Economists for Free Trade, the European Research Group (ERG) and all of the other Brexit-supporting groups must speak with one voice.

By bringing the Brexit campaign groups together, not as a new single group but through organisation and coordination, we can coordinate our efforts and support each other more efficiently and effectively. I’m drawn to the old, reliable phrase – singing off the same hymn sheet. We are not only obliged to do this, but it is our duty.

It will allow us, as a Brexit movement, to strategically counter the relentless rhetoric from those seeking to stop Brexit. However, it will also allow us to go on the offensive – to be proactive in delivering our message.

A vote to leave was not the disaster it was thought to be and nor will Brexit. Even David Cameron agrees. Our message on Brexit is innately positive and we shouldn’t hold back in delivering it. Let’s get on the front foot by talking about the benefits of free trade, regaining our regulatory independence and controlling our borders with a proper migration policy.

What happens behind the scenes is just as critical as what happens in public.

We need to unite and place a ‘lock’ on the four Brexit freedoms – control over all our laws, our finances, trade and immigration policy. It’s these powers that will give Brexit Britain a comparable advantage of being a non-EU member. This means no EFTA membership, no continuation of our membership in the Single Market and Customs Union also. And it also means no extension of our membership for two or more years after March 2019.

This is what must be delivered by the government and we shouldn’t be shy in ensuring we get this.

Cross party works best. Only a fortnight ago, I lead a delegation of cross-party political leaders to meet Mr Barnier. Digby Jones is a crossbench peer, John Longworth is the co-chair of Leave Means Leave, predominately back by Conservative MPs and John Mills chairman of Labour Leave with millions of supporters.

Jacob Rees-Mogg’s appointment as the chair of the ERG is a positive first step. Jacob is a voice of great authority of Brexit and is respect by all Brexiteers. His appointment gives me confidence that all of this is entirely possible.

We cannot afford to delay for another second – the ultra-remainers pursuit to reverse Brexit is endless.

The biggest risk to Brexit is for Brexiteers to fight with each other and become a fractured movement. By uniting, we will be unstoppable.