THE Labor Party's campaign to win the seat of Ballarat West was yesterday thrown into turmoil after sitting member Karen Overington announced her retirement.Ms Overington's decision not to stand at the November state election for "personal reasons'' was delivered in a statement released by the Premier's media unit.The announcement has sparked a flurry of action within the Labor Party as candidates rush to replace Ms Overington in the seat, which she holds by 6.5 per cent.Sources have told The Courier that candidates vying for preselection could include current and former Ballarat councillors.Lifeline Ballarat and family counselling services manager for Uniting Care Ballarat Sharon Knight last night announced she intended to seek preselection.Cr Cheryl Bromfield yesterday said she enjoyed being a councillor but could consider a preselection bid. Fellow councillor Craig Fletcher ruled himself out of the race.A spokesperson for the Premier said a preselection campaign would be run under normal process by the organisational arm of the party. A date for that vote has not been set.Ms Overington's announcement follows intense speculation over her future, as reported in The Courier last month.The death of her husband Brian from cancer in October last year and her own health problems have contributed to reduced public appearances and comments in the past six months.In the statement released yesterday, Ms Overington said it had been a great privilege to represent the people of Ballarat West during the past decade."I have decided for personal reasons to retire from politics but will continue to serve my electorate as the Member for Ballarat West until November."I feel very fortunate to live and work in a thriving regional electorate that has seen remarkable growth and change - and by working in partnership with the community, much has been achieved to improve the quality of life of the people who live here.''Premier John Brumby paid tribute to Ms Overington's dedication."Karen Overington has been a passionate, dedicated and hardworking local member so it's with great regret that she will resign from parliament after November's election,'' Mr Brumby said."I know that Karen's decision to stand down from public service has been tough but I commend her for the dedication she has shown representing the electorate.''Liberal Party candidate for Ballarat West Craig Coltman said it was obvious Ms Overington had been going through a difficult time."I like to thank her for putting the people of Ballarat West first in making this decision,'' Mr Coltman said."I wish her all the best.''He said the announcement would not change his campaign."We were always going to run a positive campaign which was issues driven. It (the decision) hasn't changed the way we will approach it.''Federal Labor member for Ballarat Catherine King said Ms Overington had left her mark on the region."Karen was certainly a grassroots politician. She always had an appreciation for the challenges facing working families, for the unemployed and for those who struggle,'' Ms King said.Ms Overington was elected to State Parliament in 1999 as Steve Bracks swept the Labor Party to a famous, and unlikely, victory over the Coalition led by Jeff Kennett.