Labor's candidate for the West Australian seat of Curtin, Melissa Parke, has pulled out of the contest after reports she told a public meeting last month that Israel's treatment of Palestinians was "worse than the South African system of apartheid".
In a statement, Ms Parke said her views on this issue were well known, but that she does not want to distract from Labor's election campaign.
"I've had 20 years' experience in international relations and law including living and working in the Middle East," she said.
"My views are well known.
"But I don't want them to be a running distraction from electing a Labor government which will take urgent and strong action on climate change.
"That's why I have decided to withdraw my candidacy."
Labor leader Bill Shorten tried to play down the shock withdrawal.
"She thought she might have another go at politics but she's decided it's not for her," Mr Shorten said.
"She's done the right thing, she doesn't want to be a distraction in the campaign."
Mr Shorten said Ms Parke had very strong views which he did not share.
There was speculation Ms Parke's preselection would force the Liberals to divert precious resources to defend the traditionally safe seat.
Political analyst Peter Kennedy said Ms Parke's withdrawal was a setback for the Labor campaign.
"Obviously the Liberal, Celia Hammond, is the favourite, but with a high-profile candidate like Melissa Parke, Labor hoped to poll very well," he said.
"I think Melissa Parke's views on those controversial issues are well known, and they were her views when she was in the parliament — and also at the time that she resigned.
"So I think that on those issues she's simply being consistent, and I guess the Labor Party should have been aware of that.
"It'll be very hard for Labor to find a high-profile candidate like Melissa Parke in such a short space of time, so I think the party will be battling to achieve the vote that it might have achieved if Melissa Parke had stayed in the race."
Mr Kennedy said it was a good strategic move for Ms Parke to bow out early.
"I'd be surprised if it had repercussions beyond WA really, but obviously Labor needs to be cautious on this issue, it doesn't want the issue blowing up and detracting from the election campaign," he said.
"Melissa Parke's views on those issues, I guess, have been controversial and have been at odds with some views within the Labor Party itself, and if she had stayed in the race there's a possibility that it could have become an issue in the Curtin electorate.
"So by bowing out now and giving the Labor Party the opportunity to obtain a new candidate — albeit at short notice — I guess it removes that issue as a potential controversy."