Let’s say you are a passionate Remainer, and one day you get a call from a British philanthropist who says she wants to spend £10m on an anti-Brexit campaign over the next year.

She doesn’t claim to be confident about how the negotiations will go or how the political landscape will change, but she wants to do something to shift public opinion.

She asks you, what is the most effective anti-Brexit communication strategy? What obvious mistakes should an anti-Brexit campaign avoid? What does it need to get right?

This is how we would answer.

1. DON’T argue for Remain

The word “Leave” has much more force than “Remain”, which barely deserves to be called a verb. “Leave” sounds like change, at a time when many people want change of almost any kind. The inadequacy of Remain applies even more acutely now than it did in 2016. Everyone who voted Leave, and a large share of those who voted Remain, now accept that, at the very least, something must happen. We had a referendum, and there was a clear call for change. “Remain” sounds like “no change”. It sounds like ignoring voters.

2. DON’T identify as Remainers

The more we talk about Remainers and Leavers, the harder we make it for Leavers to change sides. Doing so makes “Leave” sound like a belief instead of a decision, and people don’t like to change their minds about beliefs (when did you last do it?). If we make this a clash of tribes, we lose. Instead, let’s minimise differences and address common problems.

3. DON’T call for a second referendum

Calling it a “second referendum” contains the implication the first one was a waste of time. Worse, it makes us sound like sore losers. If you bet on a game of snooker with your friend, lose, and then ask for “best of three”, you sound a bit desperate, don’t you?

4. DON’T tell Leave voters they got it wrong

The torrent of scorn from disappointed Remainers over the past 18 months will only have strengthened the determination of Leave voters to stick to their guns. Nobody likes being told they are wrong. When they are, they cling to all the reasons they may be right. When we talk to Leave voters, we need to respect their reasons for voting as they did.

5. DON’T tell Leave voters they were lied to

It might feel good to vent about lies, but this is another way of evoking exactly the opposite response to the one we want. To understand why, ask yourself why you weren’t fooled by these lies - presumably because you’re too well-informed or too smart to believe them. So what does that imply about those who were? When you say “You believed the lies”, people hear, “You were stupid.” This is not clever.

6. DON’T talk about the bus

The Leave campaign’s promise of £350m for the NHS was extremely successful, and even now they will claim the money is just the other side of Brexit. Why keep reminding people of our opponent’s best message?

7. DO target Leave voters

Of course, many will never be converted. Britain Thinks found 37 per cent of Leave voters are “Die-hards” who want out of the EU at any cost. But another 16 per cent are open to persuasion. We need to focus on people of working age, who may have young kids, and who have a big stake in the country’s future prosperity.

8. DO weaponise bad news

There already has been economic bad news and there is likely to be more. We need to brand it with Brexit. The Brexit pay squeeze, Brexit price rises, a Brexit-damaged NHS. Just as a pill doesn’t have to be big to work, so it is with making bad news cut through. Marmite disappearing off supermarket shelves wasn’t the end of the world. But everyone understood it.

9. DO attack the Brexit Bill

Let’s focus minds on why we’re spending the money on this instead of on the NHS (yes, we’d have to pay it anyway, but it’s a figure that can stand in for the enormous waste of national resources Brexit entails).

10. DO make Brexit a roadblock to change

Instead of appearing to be trying to fend off change, Remainers need to argue that Brexit is stopping Britain from making the changes it desperately needs. We want Leave voters to conclude: “You know what, I’d rather be out, but this country has bigger problems to deal with first. Brexit is an expensive distraction.”

11. DO shine a light on the clown show

A better approach than “you were lied to” is to highlight how we have been let down by incompetent Brexiteer politicians. We want Leave voters to think: “I trusted them to deliver but it turns out they are clowns.” For Leave voters anxious about how things are going, this provides a face-saving out. Boris Johnson was a powerful weapon for the Leave campaign – now he is a powerful weapon for us.

12. DO have a message for voters who care about immigration

It’s hard to make the political case for free movement but it is possible to get most people behind “good immigration”. To do that we need to address the public’s core concern: that if people come here from overseas, they should have to put in before they can take out. This is what most people call fairness, and it’s a concern that goes wider than immigration: it underpins people’s feelings about the NHS, education and other public services.

13. DO make the sovereignty case for Brexit

When Leave voters say they want Britain to take back control, they are not referring to some esoteric debate about the jurisdiction of the European Court of Justice. They are saying they want the country to make rules for itself and not have rules imposed on it. Psychologically speaking, this is about dominance and submission. The fatal mistake of Remainers was to frame their case as one for compromise and power-sharing. Instead, we should argue that Brexit is weakening our country, putting us at the mercy of foreign powers. In order to make our own rules - and indeed impose them on others - we need to be in the EU and bossing it.

Ian Leslie is a writer, author of CURIOUS: The Desire to Know and Why Your Future Depends On It, and writer/presenter of BBC R4's Before They Were Famous. Rob Blackie is a marketing strategist for political campaigns.