On the surface, the elections for the National Assembly in France have nothing in common with Britain’s most recent election, held on June 8. In France, President Emmanuel Macron’s new party may take three-quarters of the Assembly. In Britain, established parties dominated the voting. But underneath, Britain and France have a lot in common with each other, and indeed with the United States.

French parliamentary elections are held in two rounds, so the size of Macron’s victory is yet to be determined. But its scale is clear. Macron could take between 400 and 445 of the 577 seats in the Assembly. The established parties on the left, in particular, all but collapsed.

The situation across the English Channel looks very different. In Britain, the newer parties seemed to weaken. The Scottish Nationalist Party lost a third of its seats. The Liberal Democrats lost vote share, as did the Greens. The U.K. Independence Party lost its only member of parliament, and its vote collapsed.

Together, the two major parties — Labour and the Conservatives — won more than 83 percent of the vote. Not since 1970 have British politics been so close to being a two-party system. And Labour and the Conservatives aren’t just the major parties — they’re also the oldest parties.

So in France, the old parties are weakening. In Britain, it seems they’ve not been so dominant in generations. But appearances are misleading — as I know all too well.

I spent the British election campaign in the city of York, inside the team of a Conservative candidate, Ed Young. While Young lost, the experience gave me insight into how British politics work today.

In Britain, it’s not unusual for new parties to come into being. It’s not easy for them to take root, but in Britain — as in any parliamentary system, like France’s — merely starting a new party is not that hard. As a result, Britain’s political parties are not as old as you might think.

The Labour Party was founded in 1900. The Conservatives don’t have a clear founding date, but 1834 is reasonable. Compare that to the United States, where Democrats date to at least 1828, and Republicans to 1856. By any reasonable measure, U.S. political parties are as old, if not older, than those in Britain.

That’s because, in the United States, we don’t found successful new parties. We absorb them into the Democrats and Republicans. From the tea party to the progressives — the list is long, but since the Civil War the story is the same. New parties win influence by taking over an existing party.

Britain, by contrast, hasn’t had many party mergers. The Conservatives absorbed part of the old Liberal Party in the early 20th Century, but that’s about it. Once they get going, British parties appear to be immune from the turmoil that regularly remakes parties in the United States. But appearances don’t reflect reality.

In fact, both major British parties have now been remade. The Conservative Party today is the party of Brexit, of British exit from the European Union. As recently as 2010, that wasn’t true. The Labour Party, meanwhile, is now the party of London, the young, government unions, and multiculturalism.

What stands out is how much Labour looks like the Democratic Party. Both used to be parties of the working class. Now they’re both parties of the New Left, backed up by unions that need taxpayer support to pay the bills. In the United States, it’s teachers unions; in Britain, it’s health care unions.

So it’s not just France where the traditional parties, especially those of the left, have disappeared. The same thing has happened in Britain and the United States, too. But in the English-speaking nations, the new parties of the left have kept the old names.

Parties across the West have changed. So don’t expect familiar policies just because a familiar name wins. It may be the same label, but it’s a new game.