The Conservatives and Labour have faced a backlash at the ballot box over the Brexit deadlock, as smaller parties and independents made local election gains.
In England so far, the Tories have lost more than 1,000 seats and 36 councils overall, while the Liberal Democrats have gained nearly 550 councillors.
Labour has lost more than 100 seats.
The BBC projects that, if results it analysed were replicated across Britain, both the Conservatives and Labour would get 28% of the total vote.
The analysis, based on 650 wards in which detailed voting figures were collected, implies the Lib Dems would get 19% and other parties and independents 25%.
More than 200 of the 248 English councils holding elections have now announced their results, with counts continuing elsewhere.
The Green Party has added 140 seats so far, but UKIP is down more than 80 councillors. Meanwhile, the number of independent councillors is up by more than 300.
Results from Northern Ireland’s 11 councils are also being announced. No local elections are taking place in Scotland and Wales.
MPs have yet to agree on a deal for leaving the European Union, and as a result, the deadline of Brexit has been pushed back from 29 March to 31 October.
While local elections give voters the chance to choose the decision-makers who affect their communities, the national issue loomed large on the doorstep.
Turnout is averaging just one or two points below the last two local elections, reversing predictions of a major drop-off in voters
Theresa May, appearing at the Welsh Conservative conference, said voters had sent the “simple message” that her party and Labour had to “get on” with delivering Brexit.
“These were always going to be difficult elections for us,” she added, “and there were some challenging results for us last night, but it was a bad night for Labour too.”
A heckler shouted at the prime minister: “Why don’t you resign?” He was then ushered out of the conference hall in Llangollen, North Wales, as the audience chanted: “Out, out, out.”