It detracts nothing from the Labour Party’s historic achievement in scooping up 410 seats in Parliament to add that the quiet scoop is that now Reform UK leader Nigel Farage is also in house in a big way, and he is making no secret of the fact that he is “coming after Labour.”

It was the chief Brexiteer’s eighth bid for election. He will now be serving as the MP for Clacton. Now he is the one drinking the milkshake, so to speak, announcing in his victory speech that one of the things his constituents can count on him to be doing at Westminster will be “coming after Labour…be in no doubt about that.”

Of the Conservative party’s defeat, Mr. Farage said that “They are literally a broad church that has no shared religion.” Another Reform UK member of parliament, Lee Anderson, who defected from Conservative party last March, kept his seat and referred to his own constituency, Ashfield, as “the capital of common sense.” 

Still just four seats out of 65o (earlier projections of 13 failed to hold up) — does it make much difference? The short answer is yes. Mr. Farage’s argument when he and his fellow MPs turn up at Westminster is that a broken system does not really represent the people and needs reform — hence the name of his party, which was founded in 2018 as the Brexit party — and he will be pushing for electoral reform. 

He is off to a brave start, making the prediction that Reform UK picked up more than six million votes in Thursday’s general election. He said that the mainstream press, “just as much as our political parties,” was “in denial” about Reform UK’s showing.

During the campaign Reform UK was sometimes polling neck-and-neck with the Conservative party in its share of the popular vote. The first past the post British voting system, though, can make it difficult for newer parties to translate voter share into parliamentary seats.

Reform UK’s quiet advance, in any event,  exposes a potentially vulnerable flank of Sir Keir’s majority. He will be the country’s first Labour prime minister since Gordon Brown. It’s a personal and some might say political triumph. Labour, though, piled up its big majority on a relatively low vote share. 

That means his and the party’s mandate could prove more shallow than it might now appear. He may have campaigned on “change” and heralded a new rising sun for Britain in his victory speech, but there is little doubt that the election was as much about British voters rejecting the Tories as it was about really embracing Sir Keir’s supposedly new and improved Labour party. 

Reform UK support was notably strong in the Brexit-supporting areas of northern England, where the party outpolled Conservatives in several seats. Yet given the size of Labour’s majority, the new government could be one of the most consequential in the British 21st century.

Mr. Farage is already seeking to capitalize on voter discontent with establishment politics, and Reform UK’s growing number of supporters will mean that Sir Keir will have that much more pressure on his team to show results. 

One of the things Mr. Farage will want to ensure is that Labour keeps Europe, or more specifically the European Union, at arm’s length. Keeping the so-called “small boats” that set off from France packed with illegal immigrants away from British shores will be part of that vigilance.

One or two botched refugee crises could start to erode Labour’s newfound popularity, something of which Mr. Farage is well aware. Reform UK’s courting of former Conservative voters is a given, with the Guardian reporting that he has “ruled out working in parliament with the Conservative party itself but opened the door to Tory MPs coming over to Reform.”

A bigger prize, perhaps even with 10 Downing Street in his sights eventually, would be to bring Labour supporters over to Reform UK’s side. That now that might seem inconceivable — but then again, for many people, so was Brexit.