Updated

Britain's dominant political parties took a hammering in local elections as Brexit-weary voters expressed frustration over the country's stalled departure from the European Union, according to updated results Friday.

Almost three years after U.K. voters narrowly decided in a referendum to leave the EU, the date and terms of Brexit remain uncertain following months of gridlock in Parliament.

The results from Thursday's local elections suggested voters blamed both the governing Conservative Party and the opposition Labour Party for the impasse.

With tallies in from almost all of the 259 local authorities that had positions up for grabs, the Conservatives had dropped more than 1,000 seats, about one-quarter of the ones it held.

Left-of-center Labour Party, which had hoped to increase the number of members serving as local councilors, lost more than 70 positions.

The Conservatives previously had members filling about 60 percent of the more than 8,000 seats that were contested in local races in England and Northern Ireland.

Elections didn't take place in London, Scotland or Wales.

Conservative Prime Minister Theresa May said the elections as a whole carried a "simple message" for both the Conservative and Labour parties: "Just get on and deliver Brexit."

An audience member at a Conservative conference in Wales had a blunter message. The party member heckled May, shouting "Why don't you resign? We don't want you."

The Conservatives and Labour are bracing for worse results in the European Parliament elections in three weeks.

Britain was due to have left the EU well before the European vote, but Brexit was postponed until Oct. 31 because May was unable to get lawmakers to approve her divorce deal with the EU.

In truth, the message sent by voters was loud but far from clear. With the country still split over leaving the EU, the rejection of both main parties reflected frustration from both pro-Brexit voters and supporters of Britain's EU membership.

"The people that voted to remain blame us for leaving and the people that voted to leave blame us because we haven't left yet," said Conservative politician Tim Warren, who lost his seat on Bath and North East Somerset Council in southwest England.

"I think they want to punish us for a lack of action in government," Warren said.

Many Labour members blamed the party's poor showing on its ambivalent position on Brexit. The party supports the decision to leave the bloc — to the frustration of many Labour members and lawmakers, who are largely pro-EU — but opposes May's divorce deal.

Talks between Labour and May's government on finding a compromise have so far failed to reach agreement.

Scottish Conservative leader Ruth Davidson said voters' message "seems to be 'a plague on both your houses' to the Conservatives and the Labour Party, who they see as a block on finding some sort of resolution to Brexit."

Labour leader Jeremy Corbyn said there was now a "huge impetus" for every lawmaker to break the logjam.

"An arrangement has to be made. A deal has to be done. Parliament has to resolve this issue," Corbyn said Friday.

The party with the biggest surge was the centrist, pro-EU Liberal Democrats, which gained more than 500 council seats to double its total. The Green Party and independents also made gains in the races that focused on local issues such as garbage collection.

"Voters have sent a clear message that they no longer have confidence in the Conservatives, but they are also refusing to reward Labour while the party prevaricates on the big issue of the day: Brexit," said Liberal Democrat leader Vince Cable.

In the May 23 elections for the EU parliament, Britain's biggest parties face additional opposition from new forces on the political scene — the anti-EU Brexit Party and the pro-European Change UK. Neither ran in Thursday's local elections.