Michael Williamson.

Jailed for a minimum of five years: Michael Williamson. Photo: AFR

Disgraced former union officials Michael Williamson and Craig Thomson have been formally expelled from the Labor Party at a meeting of the NSW administrative committee.

The expulsions are the first use of new powers bestowed upon the NSW ALP following last year's intervention in the troubled branch by then prime minister Kevin Rudd.

Last week, Williamson was sentenced to a minimum of five years in jail for defrauding the Health Services Union of close to $1 million in what a judged described as "parasitic plundering".

Admission: Former HSU official Craig Thomson.

Appealing three-month jail sentence: Craig Thomson. Photo: Penny Stephens

Thomson, Williamson's protege and a former federal Labor MP, is appealing a three-month jail sentence for stealing money for use on prostitutes and personal expenses while serving as the union's national secretary.

On Friday morning, NSW Labor's administrative committee supported a motion to expel the duo. It was moved and seconded by the party's general secretary Jamie Clements and assistant secretary John Graham.

Williamson's expulsion had previously been raised in correspondence with Mr Clements by the new HSU NSW secretary, Gerard Hayes.

Mr Graham said the expulsions meant the party was "slowly and deliberately cleaning out the Labor stable, and we challenge the Liberal Party to do the same".

Former NSW energy minister Chris Hartcher and his fellow Liberal MPs Chris Spence and Darren Webber are under investigation by the Independent Commission Against Corruption.

ICAC is investigation whether the MPs, along with current and former political staff, "corruptly solicited, received and concealed payments from various sources in return for certain members of Parliament favouring the interests of those responsible for the payments".

Mr Hartcher resigned from cabinet following a raid by ICAC on his office last December. The three MPs have had their Liberal Party memberships suspended pending ICAC's findings and now sit in parliament as independents.

Mr Hayes also strongly welcomed the expulsion of Williamson and Thomson.

"The shame heaped onto our union by Michael Williamson's actions has been lasting and real," he said.

"Our union will never allow an abuse of power and position like this to happen again. The ALP's decision to expel Williamson is welcome and necessary."

Before the federal intervention into the NSW division, expulsion motions had to go to the disputes committee for consideration.

When Labor moved to expel corrupt powerbroker Eddie Obeid last year he threatened legal action.

The new powers allow the party to directly expel members through the administrative committee.