A Labour councillor has been found guilty of falsely branding a Liberal Democrat rival a paedophile and telling electors he had sex with teenage boys.
Miranda Grell won the seat in the Liberal Democrat stronghold
Miranda Grell slurred gay Lib Dem candidate Barry Smith while campaigning for the Leyton ward in Waltham Forest Council, east London, in 2006.
Grell, 29, was convicted by magistrates of two counts of making false statements about another candidate.
She was handed a £1,000 fine and will be forced to vacate her seat.
Waltham Forest Magistrates' Court heard in police interviews Grell admitted she had discussed Mr Smith's sexuality with one local resident.
She said she told the man Mr Smith claimed to be married despite having a 19-year-old Thai boyfriend.
Grell put the mistake down to political immaturity and inexperience at campaigning.
But another resident, Caroline Dargan, told the court Grell had a similar conversation with her.
Outside court Ms Dargan told BBC London: "(Grell) just started to talk about the Lib Dem candidate. She made some suggestions about him being gay, and I sort of knew that.
"But then I felt the conversation deteriorated into her saying that he was actually interested in young oriental boys."
Grell had told the court that the accusations against her were part of a plot by rivals jealous of her election win.
The slurs were said to have 'destroyed life' for Barry Smith
But District Judge John Woollard said: "I cannot accept the conspiracy theory put forward by Miss Grell in any shape or form.
"It doesn't fit in with the nature of the police investigation and the evidence of what people said."
He told Grell: "It is a sad day. In furthering the interests of your community you fell into an error on two occasions in making statements that were untrue and damaging to one of your fellow candidates."
Mr Smith, 56, has a long-term 39-year-old Malaysian partner and served on Waltham Forest Council between 2003 and 2006 before moving to northern England.
Outside court councillor Keith Rayner, Lib Dem leader for Waltham Forest, said the case had been "traumatic" for Mr Smith.
"It has destroyed his life for him and his family," said Mr Rayner. "He has now had to move away from the authority."
Unless she appeals against her sentence within three months, Grell, who was also ordered to pay £3,000 costs, faces a three-year ban from holding public office and will be forced to vacate her seat, a Waltham Forest council spokeswoman said.
A Labour Party spokesman said Grell had been suspended from the party
pending an internal investigation.