In a day of drama that saw more than a dozen ALP members denied the chance to vote for an A ward candidate following the theft of party records, Councillor Ken McDonell was defeated in Eward.

Cr McDonell, who has served on Sutherland Shire Council since 1987, was defeated by Damian Ogden.

Mr Ogden, a union organiser and secretary of the ALP's Menai branch, beat Cr McDonell in a fierce contest at Tradies, Gymea, on Saturday.

The preselection win means Mr Ogden will now take first spot on the Labor party's E ward ticket when the Sutherland Shire Council elections are held in September.

In A ward, Councillor Scott Docherty easily beat Stephen Jones, who was able to run despite earlier reports that he had abandoned the contest.

Mr Jones, a member of the Gymea-Grays Point branch of the ALP, had hoped to win preselection in A ward.

His nomination had won the support of six Cronulla branch members, guaranteeing him a place in the preselection battle.

However, hopes of turning this support into votes were dashed after a car containing records for Cronulla branch members was stolen.

This meant the majority of Cronulla branch members could not prove their ongoing membership and attendance at meetings, making them ineligible to vote.

Only life members of the two branches that make up A ward and those members of the Caringbah branch who had proven their ALP credentials were able to vote.

This delivered an easy win to Mr Docherty, who is a member of the ALP's Caringbah branch and has represented Labor in C ward since 1999.

Also recording a preselection win was Mark Buttigieg.

The former ALP candidate for the Federal seat of Cook will go into the Sutherland Shire Council elections as the Labor party's number one choice for C ward.

Councillors Phil Blight and Jan Forshaw were unchallenged and will contest their respective wards.