Labour has lost control of its four remaining county councils in England after damaging defeats in what were once seen as traditional strongholds.
It lost Staffordshire, Lancashire and Derbyshire to the Conservatives for the time in decades while Nottinghamshire passed to no overall control.
Labour had controlled Derbyshire since 1981 and had been in power in the other three councils since the early 1980s.
Deputy Leader Harriet Harman said the results were "disappointing".
As the results of elections to 34 English councils are being declared, they indicate that Labour's vote has been squeezed across the country.
According to the BBC projections, Labour's share of the national vote has fallen by three points since 2004 to 23%, behind the Tories on 38% and the Liberal Democrats on 28%.
Derbyshire's loss means it passes out of Labour control for the first time since 1977 as the Conservatives took 19 seats to gain overall control.
The Conservatives also took control of Staffordshire, with Labour winning in only two out of 62 wards called so far.
The BBC's Midlands political editor said this result had been greeted with despair by Labour, with one former councillor describing the result as a "complete wipe-out".
The Tories picked up 18 seats in Lancashire, another historic Labour heartland, to gain control of the council for the first time since 1981.
But the BNP won a seat in Burnley, one of two it has picked up across England so far.
The BBC North East political editor Richard Moss said Labour had suffered some "major reverses" in the region in what had been a "terrible day" for the party.
Ms Harman said the backdrop to the election was very difficult for Labour given voters' anger over the expenses scandal and the recession.
"I think that we're all facing disappointment in these results in the Labour Party," she said.
"We have to listen to what the voters are saying," she told the BBC. "We have to understand and learn the lessons."
Tony Lloyd, chairman of the Parliamentary Labour Party, said it was clear beforehand that the results would be bad.
"We have got to demonstrate that the policies we have got are those which relate to what ordinary people want," he told the BBC.
According to the BBC projections, the Greens are averaging 12% of the vote in this year's poll, with UKIP and the BNP on 14% and 11% respectively.