The ruling Tory-Liberal Democrat coalition of Wolverhampton City Council was today on the brink of collapse after the city's schools boss withdrew her support.
Lib Dem councillor Claire Darke said she could no longer go along with keeping the parties in power after a by-election left the city with 30 councillors on each side.
The nature of numbers - 30 Labour, 25 Tories and five Lib Dems - means an abstention by a member of the controlling group would allow Labour to take control. If votes are tied, the casting vote of Mayor Malcolm Gwinnett, a Lib Dem, carries in favour of the coalition.
Councillor Darke, cabinet member for schools who who represents Park ward, said: "It is not only politically wrong, but morally wrong, to keep in power a coalition rejected by the majority of the electorate in Wolverhampton. The by-election in Bilston in July meant that Labour now has the electorate's support."
Disappointed Tory leader Councillor Neville Patten said today: "This has come as a surprise. I don't know where we go from here."
Labour leader Roger Law-rence said: "We've had indication some Lib Dems wan- ted to talk to us, but not all."
Councillor Gwinnett said he was seeking a legal ruling to ascertain whether Councillor Darke's party whip requires her to support the coalition.