“Inflection point”: the ongoing major realignment in British politics has reached a significant moment as a poll shows Nigel Farage’s insurgent Reform Party ahead of the centuries-old establishment Conservatives for the first time ever.

Polling by YouGov — a pollster founded by a former Conservative Party government minister — has placed Nigel Farage’s Reform UK Party at 19 per cent. While this is just one point clear of the Conservatives, who are polled at 18, this is a significant moment in British politics as it is the first time the Conservative Party has ever been credibly challenged from the right in a General Election.

The Times poll was taken after the Conservatives launched their election manifesto — political platform for the coming July election — and the result will be a crushing blow suggesting the raft of promises contained therein failed to slow their grinding collapse with the voting public.

A political force since the English Civil War in the 17th century, the Conservatives have acted as the default party of government in the UK for all of modern British political history, sharing the two-party system with the Liberals at first, and for the past century with Labour. It remains the case Britain has an electoral system which heavily favours established parties, and Farage himself has made clear there is a “magic number” in terms of results where votes actually start converting into seats.

The polling result is a major development in the race to decide who will oppose and be the counterbalance to the next British government, which this poll again confirms will very likely be the left-wing Labour Party, who tonight scored 37 per cent, enough for a heavy majority in Parliament.

Brexit leader Nigel Farage hailed the result tonight, saying in a short video published before he joined the latest leaders’ debate on live television, to say: “We have now overtaken the Conservatives, we’re in second position in the country. In fact we’re leading the Conservative Party in every single region apart from Scotland.

“This is the inflection point. The only wasted vote now is a Conservative vote. We are the challengers to Labour and we’re on our way… A vote for the Conservatives is now a vote for Labour.”

British polling, which has some history of failing to call big votes — like Brexit, for instance — came with a health warning, as ever. YouGov themselves said of their own results: “Obviously all polls have a margin of error, so we can’t conclude for certain that more voters now back Nigel Farage’s party over the Conservatives. But what it does make clear is that at the very least the Conservatives and Reform are at a very similar level of support to each other.

“That in itself is remarkable given how close we are to an election when we might otherwise have expected smaller parties’ votes to be squeezed.”