The Conservatives have lost any chance of regaining their majority on Peterborough City Council after suffering a by-election defeat.
Labour and Co-operative candidate Matthew Mahabadi comfortably won the previously Conservative-held seat of East ward with a majority of 789.
Tory candidate Jay Beecher was second ahead of UKIP's Graham Whitehead and Jelana Stevic of the Liberal Democrats.
The by-election was called after the death of Conservative councillor Marcus Sims.
Mr Mahabadi said: "If you want more cuts, more driving down of services, you vote Tory.
"People wanted someone with the energy, the enthusiasm, to really make a change, and I have that."
After last year's local election the Conservatives held 31 of the 60 seats on the council, but following the death of Mr Sims and the resignation of David Sanders that left the council under no overall control.
The East ward result means they now hold 29 of 59 seats and will be unable to regain their majority, even if they win a future by-election in Eye, Thorney and Newborough.
However, support from independents means the Conservatives should be able to pass legislation as the biggest party.
Mr Beecher praised Mr Mahabadi's "clean" campaign. He said: "We ran a strong campaign. There were numerous factors working against us. However, we stayed positive, determined and I will continue to work within the community."
Ms Stevic said: "I'm disappointed that I did not get a few more votes but I'm glad I got the votes that I did. It's the first time the Liberal Democrats have been in East ward and we've got a foothold in there.
"Watch this space for next time."
The turnout for the by-election was 53.1 per cent.
Matthew Mahabadi (Labour and Co-operative) - 1,900
Jay Beecher (Conservative) - 1,111
Graham Whitehead (UKIP) - 358
Jelana Stevic (Liberal Democrat) - 332