A new Westminster Parliament opinion poll has shown a massive shift in British political attitudes, with neither of the legacy parties leading and the Brexit and Liberal Democrats parties lead the pack.

The poll by YouGov has the Liberal Democrats in first place on 24 per cent. They are closely followed by Nigel Farage’s new Brexit Party, which won last week’s European elections in a landslide, on 22 per cent.

Labour and the Conservatives make up joint third place on 19 per cent each. The Green Party came in fifth place in the poll with eight per cent while UKIP and Change UK only recorded one per cent apiece.

The poll is the first since the end of the Second World War to not have either Labour or the Conservative Party in one or both of the top positions.

You Gov have released a poll showing the Lib Dems top in the country, with @brexitparty_uk second. They did not have the BP option on the list and we were hidden in ‘others’. Looks like an establishment attempt to suppress the truth. #FakePolling — Nigel Farage (@Nigel_Farage) May 31, 2019

The poll is also the first since 2010 to show the Lib Dems in a leading position. The last time was before the 2010 General Election in which the Liberal Democrats went into coalition with the Conservatives, a decision that nearly destroyed the party in its aftermath.

The strong polling for the Brexit Party comes despite the fact the party wasn’t even listed on the main list of options for those responding to the survey, having been nestled away under ‘other’.

The decision to count the party as a minor group comes despite a historic win for the newly formed party in last week’s European Parliament vote, a national election, in which the Brexit Party won 31.6 per cent of the vote. The Liberal Democrats came a distant second with 20.3 per cent of the vote.

The new data is the latest evidence that Brexit will be the key dividing issue in the next General Election, with 70 per cent of respondents saying that Brexit was the key issue facing Britain.

Will write about it elsewhere (needs more than 280 c), but always tricky decision when to promote a party to the main q, and already testing & reviewing it same way we did for UKIP before moving them up (at same time, also need to work out why we overstated Brexit party at Euros) — Anthony Wells (@anthonyjwells) May 31, 2019

The next big test for political parties will be the hotly contested Peterborough by-election which was announced when former Labour MP Fiona Onasanya was recalled by her constituents after going to prison for perverting the course of justice. The by-election is seen as a vital litmus test for the newly-formed Brexit Party in particular as the Peterborough constituency voted 60.9 per cent to leave the EU.

A strong sign that the Brexit Party may win its first Member of Parliament in Peterborough was that they came first in the EU elections in the constituency, doubling the votes of the second placed Labour Party.