Victorian Cabinet Minister Mary Wooldridge has lost a preselection battle for the safe Liberal seat of Kew, throwing her political future into doubt.

The Community Services Minister nominated for Kew after her existing electorate of Doncaster was abolished in a recent distribution.

But she faced stiff competition from Tim Smith, the former mayor of Stonnington, who had strong support from the party's rank-and-file.

Today a meeting of almost 300 local branch members voted to endorse Mr Smith to run for the seat.

The result comes despite Premier Denis Napthine taking the unusual step of intervening in the contest, writing a letter to branch members urging them to back Ms Wooldridge.