Odds tighten around Kevin Andrews challenger Keith Wolahan

Former special forces commando Keith Wolahan’s campaign to unseat Liberal stalwart Kevin ­Andrews in the Melbourne seat of Menzies is gathering pace.

Former special forces commando Keith Wolahan’s campaign to unseat Liberal stalwart Kevin Andrews in the Melbourne seat of Menzies is gathering pace, with party powerbrokers expecting Sunday’s preselection showdown to go down to the wire.

Attempting to be the first Liberal candidate to oust an incumbent Victorian MP in a preselection since 1990, Mr Wolahan has distributed a five-page brochure to Menzies branch members in a pitch for generational change.

The Australian understands ex-supporters of Mr Andrews – a former defence, immigration and employment minister under John Howard and Tony Abbott – have shifted behind Mr Wolahan ahead of the preselection contest.

Mr Wolahan’s brochure includes endorsements from former Menzies FEC chair Hal Grix and retired Brigadier TJ Nolan, a former Commander of the Special Forces.

The campaign brochure sent to 300 Menzies preselectors spruiks Mr Wolahan’s record in the Afghanistan War, his work as a barrister and Liberal activist, and promotes his conservative values.

Mr Grix, who met Mr Wolahan in 2006, said the ADF veteran had the “experience, skills, judgment and character we need for the future”.

“I cannot remember our party ever having an opportunity like this – to be represented by a genuine local with a young family, who is a successful and effective barrister … who has served his country valiantly on the battlefield.

“I feel this is a real opportunity not to be missed. He will engage with the electorate. He will engage with members. He will identify with their local aspirations.”

Brigadier Nolan said he “wholeheartedly” endorsed the former commando, who served in Timor and Afghanistan, to be preselected in Menzies.

The brochure promoting Keith Wolahan’s candidacy.

While Mr Andrews, the Father of the House as the longest continuously serving MP, has won the backing of Scott Morrison, John Howard, Tony Abbott and Josh Frydenberg, Liberal insiders say the weekend preselection meeting is “too close to call”.

A key backer of the 65-year-old, who believes the veteran MP will win on Sunday, told The Australian: “Keith represents those who are still angry at Kevin’s role in deposing Malcolm Turnbull.”

The Andrews supporter said Mr Wolahan was not a “conservative candidate” and argued that generational change should occur in opposition and not government.

“This is a time for stability and experience,” the backer said.

A backer of Mr Wolahan pushed back against claims the father-of-two was not a conservative, declaring the contest was between “a young conservative and an old conservative”.

A number of senior Victorian Liberals believe Mr Wolahan had the edge going into the preselection meeting but conceded it would be tight.

Several Liberal sources said generational change was the main factor among Mr Wolahan’s support base.

“There’s a lot of goodwill towards Kevin Andrews but it’s been 30 years,” one senior Liberal member told The Australian.

“Does he really want to close the door on a young person with a lot of potential so he can have another three years? For what?”

Another senior Liberal also disputed claims Mr Wolahan was a moderate: “If he was running against Tim Wilson or Katie Allen, he’d be called the conservative candidate.”