Election 2019, here we come? The DUP’s leader, Arlene Foster, has used her eve-of-conference interview with the BBC to say that in the event that Parliament successfully passes the EU-UK withdrawal agreement into law, her party will “revisit” its confidence-and-supply deal with the Conservative party.

Now, of course, “revisit” means a lot of things. It could simply mean that more money will have to be ponied up, or that a prerequisite for the continuation of the Conservative-DUP alliance is that Theresa May is ushered into retirement. As the Conservative-DUP accord is up for renewal in 2019 anyway and May is not going to last long past the successful signing of a withdrawal agreement that might not mean very much.

But equally it could mean that we will be heading for an election sooner rather than later, assuming that is that the government can eventually find a way to enshrine the withdrawal agreement into law.

For Jeremy Corbyn, it feels like as close to a win-win proposition as you can get in politics. If the government can’t pass the withdrawal greement, the United Kingdom leaves without a deal and the resulting economic shock is a major boost to his hopes of winning the 2022 election. If the government can pass the withdrawal agreement, then he gets an election in 2019.

It’s worth remembering the scale of the task in front of the Conservative Party if they want to remain in office next time. In order to not emerge as the governing party after the next election, Labour would have to be the worst-performing opposition since 1983 and to do worse than any party has done after losing three elections in a row ever. In contrast, the Conservatives would have to do better than any party seeking a fourth term in power ever. I’m not saying these things can’t happen, it’s just that it is a very, very big ask for the Tories to retain power and it would be a remarkable and noteworthy result if Labour failed to take office after the next election.

So any election at any time is pretty good for Labour. But as it happens, an election in 2019 makes a lot of sense for almost everyone else too.

For the DUP, the politics of bringing the house down in 2019 are open and shut, too. If they don’t, the Conservatives will have rode over their major red line and lost…what, exactly? Go to the country in 2019 and the DUP have a readymade message for the election, which is that the only way to prevent further barriers appearing between Northern Ireland and the United Kingdom is to elect as many DUP MPs as possible, giving them a good chance of not only equalling their 2017 result – their best performance at Westminster in their history – but perhaps even surpassing it. The SNP will be able to make a similar case in Scotland, too, albeit on the opposite side of the argument.

And for the Conservatives, it is difficult to see when they could be better placed to fight and win a fourth term in office. The United Kingdom will be out of the European Union with no economic ill affects as we will still be within the economic project. With the final trade agreement yet to be negotiated, the party will be as close to united over Europe as it will ever be. There will still be divisions, but ask yourself this: would you rather lead the Conservative Party into an election when the free trade agreement is just some flowery language on which most Tory MPs can agree on what the words say even while disagreeing on the meaning, or when the free trade agreement actually exists on paper?

Any new Conservative leader will have won the backing of a significant number of their MPs and of party members. They’ll be able to say that they have done Brexit, that the economy hasn’t gone off a cliff, despite the protests and opposition of the unpatriotic liberals on the other side. They will yet to have grappled with any of the trade-offs of the final trade agreement.

The only party for whom it would be very difficult election would be the Liberal Democrats, fighting as the anti-Brexit party in a situation in which Brexit had decisively happened but nothing had yet changed, at a time when they have little money. The Conservatives are the second-placed party in eight of the 12 Liberal Democrat-held seats, making them the biggest beneficiaries of a Liberal collapse.

Which isn’t to say that the Conservatives would win that election or even be able to continue in office as they are now. They would still need to defy all electoral history to remain in power. Labour should still be seen as the heavy favourites. It’s simply to say that given the choice between going to the country after a prolonged civil war over the shape of the free trade agreement, or after a no deal exit, any thinking Tory should take the opportunity with both hands.