The former deputy mayor of Cambridge has resigned her seat on the city council after being found guilty of benefit fraud.
Berni Callaghan, 52, was found guilty of over-claiming £740 in council tax and housing benefits when she appeared at Peterborough Magistrates on Friday.
She was given a conditional discharge and ordered to pay £2,000 costs.
In a statement Miss Callaghan said she could no longer expect to be trusted by the electorate or her party.
The court heard she had failed to disclose shares she held in Anglia Water, Alliance and Leicester and the Halifax when claiming the benefits.
On Tuesday, Miss Callaghan said: "I have been convicted by the courts of claiming £740 to which I was not entitled which I repaid before my case came to court.
"The Labour Party and the electors of Coleridge have trusted me to represent their interests on Cambridge City Council since I was first elected in 1999; and I have tried to do that to the best of my ability.
"In view of the verdict of the court, I can no longer ask for or expect that trust, which I deeply regret. Without it, I cannot continue to represent either Coleridge Ward or the Labour Party."
Leader of the Labour Group on Cambridge City Council Ben Bradnack said: "The Labour Group believe that Berni has acted properly in resigning her seat after receiving the judgment of the court.
"But we also want to record our appreciation of the contribution that she made as a member of our group, and to the council as a whole, including her time as a particularly hardworking deputy mayor; and also as a popular councillor for Coleridge Ward."
Miss Callaghan's resignation would lead to a by-election, he added.