The Liberal Democrats stormed to victory in London as Labour lost half their seats and the Conservatives were wiped out.
The Lib Dems won the popular vote over the city, including in more than a dozen key Labour and Tory-voting areas, taking three of the region’s eight seats in the European Parliament.
Labour won two, down from four in 2014, the Conservatives lost both their seats while the Brexit Party gained two, the Greens retained one and Ukip lost one.
A jubilant group of Lib Dem supporters dressed in yellow cheered and hugged shortly before the result was officially announced at London City Hall.
Irina von Wiese, Dinesh Dhamija and Luisa Porritt will now serve as MEPs for the party.
Ms Porritt said: “I’m absolutely delighted that the position we’ve had against Brexit from the outset since we had the referendum is finally paying off for us.
“I knew it would be on a knife edge, the polls in the last week suggested I might be on the cusp of getting in, as third on the list, but we had no idea it would go our way, even up to the last minute.”
She added: “The main thing (from these results) is that the Liberal Democrats are back on the political map and third-party politics is here again to stay in the UK.”
One of the Lib Dem successes was in Jeremy Corbyn’s borough Islington, where the party beat Labour into second place.
Claude Moraes, elected for a fifth time for Labour along with Seb Dance, said it was a “slight disappointment” not to come top in the capital.
He said: “The Conservative Party were not elected at all in London, which is clearly a verdict and a punishment by the electorate to wipe them out in London all together.
“We came second but we had a result that was reasonable given how difficult the context was for this election, and from that result we have to learn in the Labour party, and we have to ensure that in the coming months we build a positive agenda worthy of the people who voted for us in relation to Brexit.”
The turnout figure across London was 41.3%, up from 40.1% in the 2014.
New Brexit party MEP Lance Forman said in his acceptance speech: “The Brexit party message is one of hope for people across the country and it must prevail.”
His colleague, Benyamin Habib, said he had picked up on an “element of dejection” amongst Leave voters while campaigning and said anecdotal evidence suggested that they “didn’t really come out in the numbers that they could have come out”.
Mr Habib said: “I thought one (seat) was in the bag… but two is great, three would have been a very, very brilliant result.”
He added: “It’s not a flash in the pan, you watch us, you keep an eye on us.”
Scott Ainslie, elected for the Greens, said Londoners had said “yes to Europe and no to climate chaos”.
The party beat the Conservatives by more than 100,000 votes, coming fourth across the region.
He said: “The result shows there is strong support in London not only for remaining in the EU, but for policies that tackle inequality and the causes of Brexit. This is a resounding yes to taking bold action on the climate emergency.”