Next week, when Britain goes to the polls, the crucial battlegrounds will be in the Midlands and the north of England, where traditional working-class Labour voters who support Brexit are being lured by Boris Johnson’s pledge to “Get Brexit done”. Many are considering voting Tory for the first time.

As someone raised in a northern working-class town and whose dad was white and working-class, I understand the frustrations that led to Brexit (if my dad was still alive he may well have voted leave), and why so many people want the referendum result to be swiftly enforced. Over the past few weeks I’ve read a lot of articles where remainers talk to remainers and leavers to leavers. So let me reach out, respectfully, from a remainer to a leaver, and ask that you think twice about casting your vote for the Conservatives.

1. “Get Brexit done”. Really? It’s a comforting thought that, after this Christmas election, Britain will have left the European Union within weeks. But what kind of nation will we be after that? Division will run deep in our society, with the 48% (16 million) remain voters believing the Boris Johnson Brexit is very different to that promised back in 2016: out of the single market, out of the customs union, and a border down the Irish sea. None of this was on the side of the bus. And that’s not even to mention the fact the Brexit isn’t even “done” till a trade agreement is reached, which will likely take years. No deal could well be back on the table in a year’s time.

Though a swift end seems appealing, remember: Brexit is for life, not just for Christmas

2. Brexit is for life … Yes, the years of negotiation have been agonising. But there are two main reasons for this: first, Theresa May drew up contradictory red lines that required a hard border in Ireland. And second, leaving the EU after more than 40 years was always going to be a complex process. Think of it like buying a home: if the property survey shows up unforeseen problems, the answer is to resolve them first, rather than press ahead for a move on an arbitrary date regardless of the consequences. From chlorinated chicken to medical supplies, to ferry companies with no ships, there has been no shortage of unforeseen problems. It’s not surprising there have been delays. Though a swift end seems appealing, remember: Brexit is for life, not just for Christmas.

3. The Tories have a record for cheap slogans. Only two years ago Theresa May went into the election saying: “I’ll deliver Brexit.” How did that go? Before that, David Cameron pledged to eradicate the deficit and to slash immigration. Both targets are now scrapped. Johnson has said: “We’ll leave Europe on 31 October, no ifs or buts.” He said he’d rather “die in a ditch”. Slogans are simple – reality is a lot more difficult.

4. Johnson despises people like you. In a Spectator article he wrote that working-class men are “likely to be drunk, criminal, aimless, feckless and hopeless”. Johnson is not your friend, your ally, or someone who’s looking out for you. In the same article he attacked single mothers and their “ill-raised, ignorant, aggressive and illegitimate” children. When challenged, he says dismissively: “I’ve written millions of words.” But those words had the clear aim of holding up the working-class and single mothers to ridicule and moral condemnation in a magazine catering for the rich and powerful.

5. Johnson picks on the weak. His attacks on black people (“watermelon smiles”, “piccaninnies”), Muslims (niqab wearers look like “letterboxes” and “bankrobbers”) and gay people (“bumboys”) are now well known. Last week another quote emerged. “Islamophobia – fear of Islam – seems a natural reaction,” he wrote, again in the Spectator. “Judged purely on its scripture – to say nothing of what is preached in the mosques – it is the most viciously sectarian of all religions in its heartlessness towards unbelievers.” If there’s one consistent theme to Johnson’s writing, it’s that he picks on the weak, those who don’t have a media platform to answer back.

The Tories may think they've already won – but the stats tell a different story | Ell Smith Read more

6. In contrast, Corbyn always fights for the underdog. While Johnson was smashing up restaurants with his Bullingdon mates knowing he’d never have to worry about the law, Jeremy Corbyn was campaigning to make life better for ordinary working people of all backgrounds. For a fair tax system in which the rich pay their share; against factory and pit closures; and against the sell-off of Britain’s national assets. And he went further: he spoke out for the rights of black people and ethnic minorities facing discrimination and harassment; for women’s rights; for gay rights; and for dialogue with Northern Ireland’s republicans. All of these, at the time, were unpopular causes and were pilloried in the press as “loony left”. Yet all, today, are accepted as mainstream – some even lauded as a sign of “British values”.

7. Labour and antisemitism. Corbyn’s critics are right to say the party should have handled its complaints better and faster. But paradoxically, what’s given antisemitism such a high media profile over the past couple of years (compared to Tory party Islamophobia, which is widespread but barely receives any coverage), is that fact that Labour members care so much about it and will not stop until it is driven out of the party.

8. How to unite the country. If Britain is to leave Europe then let it at least be done in a way the nation can unite behind. We now know far more about what it really means than we did in June 2016. If it really is still the will of the people, there should be no problem in getting another majority for it. But this time, it would be on the basis of a clear outcome that has been negotiated in advance. A Corbyn-negotiated Brexit (the basics of which have already, in principle, been met warmly by EU leaders) would protect jobs, protect trade, and protect workers’ rights. Johnson’s deal does none of those things. Remainers would still regret a vote for Brexit, but would abide by it and move on. The Tories call this “dithering”. Yet they’ve bungled Brexit for three and a half years, and we’ve still not left the EU. Corbyn could resolve this Tory-created crisis within six months.

9. Remember why you’ve always voted Labour. If Britain leaves with Johnson’s deal on 31 January there’ll certainly be a strong sense of relief. But it will be short-lived. Because then we’ll face five more years of Conservative government, and let’s not forget what that means: more cuts (the Tories say they’ll protect the NHS and the police but almost everything else will likely be slashed back); more job insecurity; more homelessness; more demand for foodbanks; fewer local services; no plan for social care; tax cuts for the richest; and no investment in the green economy of the future. If Johnson’s elected, we’ll be back in a harsh, Tory Britain. Don’t forget what that feels like.

10. A question of character. Who do you trust? One of the candidates for prime minister has a decades-long track record of campaigning for those the powerful don’t care about: working people, sick and disabled people, minorities, and the weakest and most marginalised. The other has a decades-long record of looking out for himself, vilifying the vulnerable, lying and cheating. He won’t even say how many kids he has. If you think the second of these is the man who can unite Britain and lead us into a brighter future then, once more, I respectfully urge you: please think again.

• Joseph Harker is the Guardian’s deputy Opinion editor. He is a former editor and publisher of the weekly newspaper, Black Briton