Former Howard minister and Victorian Liberal party president candidate Peter Reith has suffered a stroke.

The former industrial relations minister in prime minister John Howard's government has been campaigning to unseat Liberal state branch president Michael Kroger.

Party members grew concerned for Mr Reith when his speech became slurred at a candidates' forum organised by the Albert Park Liberal party branch on Tuesday night. Both Mr Reith and Mr Kroger addressed the gathering.

He was hospitalised on Wednesday morning and was in a stable condition later in the afternoon, sources close to him said.