Opposition Leader Bill Shorten expects the Greens will cop a backlash if they preference the Liberal Party in some key Labor seats.
A Parliamentary Library analysis of 2015 NSW state election results and proposed redrawing of seat boundaries shows deputy Labor leader Tanya Plibersek's electorate of Sydney is at risk of falling to the Greens on the back of Liberal preferences.
Greens leader Richard Di Natale says he's open to finding "common ground" with the coalition and is confident his party can win the inner city seat.
"We've worked with the coalition in the past ... and we will work with whoever the government of the day is," he told reporters in Sydney on Friday.
But he acknowledged the parties do have their differences.
"On most things, the Greens and the coalition are poles apart," he said.
"And I think that's the message here - certainly in those Labor-held seats - it's that voters across the country are saying Labor is no longer a party of opposition to a coalition government."
Mr Shorten said his "money" was on Ms Plibersek and Anthony Albanese, who is also under threat in neighbouring Grayndler, according to the analysis.
"They work hard locally. They're outstanding contributors to my leadership team," he said.
"Furthermore, if the Greens preference the Liberals, that speaks volumes and I think the Greens will suffer a backlash if they ... pick the policies of Tony Abbott on climate change over Labor."
Ms Plibersek holds her seat with a 14.7 per cent margin, but says she's never taken it for granted since first winning it in 1998.
"I have fought every election as though my seat was a marginal seat," she said.
"There can be very big shifts in a seat like mine because there are lots of new residents every time I face the ballot box."
The Labor frontbencher said the fact that the Greens had done deals with the coalition such as cutting part-pensions would not play well for the minor party.
"We know that the Greens have supported the government in a number of areas that I would think would be quite controversial with their voters."
