The man picked by the Liberal Party to run in the hotly-contested Western Australian federal seat of Stirling has defended the process which saw him chosen over four female nominees, saying preselectors were given complete freedom.

Key points: The Liberal Party has been criticised for a lack of female members

The Liberal Party has been criticised for a lack of female members Several high profile women will be stepping down at the next election

Several high profile women will be stepping down at the next election But Stirling candidate Vince Connelly says the selection process is democratic

Former army officer Vince Connelly hailed the preselection as "incredibly democratic", unlike the process he said took place in the ALP where "factional bosses and union heavyweights are able to dictate which candidate will be put forward".

He was chosen to run after frontbencher Michael Keenan announced he would retire at the next election.

But he was the only male candidate in a field of five, sparking renewed claims of gender bias within the Liberal Party.

Deputy Labor leader Tanya Plibersek, campaigning in Perth earlier this week, said Prime Minister Scott Morrison pretended he wanted more female candidates but was "impotent" when it came to actually pushing this change.

Mr Keenan today acknowledged he had wanted to see a female candidate succeed him in Stirling, but said it was the local party branch's decision and Mr Connelly was a friend and an "exceptionally good candidate".

Mr Connelly, a vice president of the Stirling branch and a Scarborough local, said each nominee was given the same opportunity to convince preselectors.

"There were both men and women as part of the selection committee and I feel like all five of us candidates had every opportunity to put forward our case," Mr Connelly told reporters.

Shorten hit by Liberal 'scare campaign'

Mr Keenan and Mr Connelly were campaigning in Stirling to denounce Labor's proposed changes to franking credits refunds on company dividends, as Opposition Leader Bill Shorten landed in Perth for a half-day visit.

Mr Keenan said he hoped while Mr Shorten was in the west he would talk to people who would be affected by his policy.

"It's the wrong policy, it comes at the wrong time and it hits people that should've been able to provide certainty to their retirement incomes and obviously pensioners as well," he said.

Bill Shorten promised $3 million for railcars if Labor wins the election. ( ABC News: Nicolas Perpitch )

The Liberals sent a truck to Mr Shorten's first media event at the North Metropolitan TAFE in Midland, brandishing a billboard that said Mr Shorten's "new tax will punish retirees".

But the Opposition Leader dismissed it as a scare campaign.

"Wouldn't it be good one day if you saw a Liberal billboard with something positive to say about anything?" he said.

"But that's not what they're going to do. You know, the reality is this is a Government that's run out of government. We've only got three more days of Parliament probably.

"They haven't got any legislation, they're not interested in doing anything other than scaring people."

Mr Shorten was at the TAFE, in the Liberal-held marginal seat of Hasluck, to announce Labor's promise to spend $3 million if elected to equip trainees to build railcars for the McGowan Government's Metronet urban rail network.

Premier Mark McGowan has promised 246 railcars will be built at a nearby Bellevue manufacturing centre.