Prime Minister refuses to answer revelations Turnbull's son is campaigning for an independent

The Prime Minister wouldn't bite over revelations by 9News that Malcom Turnbull's son Alex is helping the campaign of one-time Liberal MP turned Independent Julia Banks, to unseat Health Minister Greg Hunt.  

She's one of four Independents benefitting from unusual and similar funding structures.

"The questions about this ‘Independents Inc’ issue is really for the independents to answer," he said, while campaigning in Sydney’s Inner West today.

But one of the targets hit back

Greg Hunt said: "They should probably be upfront that they're not independent and that they're not grassroots."

Alex Turnbull confirmed his involvement in a series of tweets.

Starting with "hell yeah”, "Rolling climate change deniers and racists and getting sensible people into parliament - what's not to like?" before deleting them.

Opposition Leader Bill Shorten was happy to milk it at the Easter Show.

"The Liberals didn't object to Turnbull’s money when it was going to them," he said.

Meanwhile, three Liberal candidates in Victoria have been forced to withdraw over constitutional concerns.

Morrison, said: “They've identified the problem, they've fixed it and I'm pleased they've done that because that's what I expected them to do."

Bill Shorten can't promise there won't be accidents in his party.

He said: "I can guarantee that our party is doing everything it can to eliminate any constitutional doubt."

The Opposition's lost one too.

Melissa Parke pulled out of the race for the West Australian seat of Curtin because of her views on Israel and Palestine.

Shorten, said: "She has very strong views, I don't share those views.

"She's felt in the context of this election campaign, she'd become a distraction."

Both leaders took a break from the election race to watch a horse race - seeing Winx storm to her record victory.