Liberal candidate for Wentworth Dave Sharma has been confronted by a group of anti-Adani campaigners while addressing the media in Rose Bay.

Polling booths have opened for today's by-election in the eastern Sydney electorate, with the Liberal Party facing a tough fight to retain the seat.

Mr Sharma was surrounded by the protesters during an impromptu media conference.

"Well I've served in a war zone in Bougainville and in the Middle East, so I've seen some challenging times," Mr Sharma told reporters, while protestors chanted "stop Adani, climate action now".

Mr Sharma said climate change was a "global challenge" and he supported the Paris agreement.

"I'm putting myself forward as the best candidate to help rebuild the party … [and to] get the Parliament refocused on the issues that matter to the country."

Anti-Adani activists surround Wentworth's Liberal Party candidate Dave Sharma. ( ABC News )

Labor candidate says he's confident

Labor candidate for Wentworth Tim Murray said he was feeling confident about today's by-election despite the battle being framed as a two-horse race.

Most of the focus has been on Mr Sharma and independent candidate Kerryn Phelps as the main contenders for the seat.

Mr Murray said he was hearing positive feedback from voters all morning.

"I think the media has positioned it as a two-horse race in the last week. However, our ground game has been excellent, our volunteers and people are telling me they're voting for me," he said.

Liberal Party volunteer Kevin Berry described the atmosphere at the polling station at Rose Bay, in the heart of the electorate, as "electric".

"I've done over 20 elections and this is the first time at 8'o'clock we've had a queue."

"It's quite extraordinary the level of interest in the election this time around. I think the quality of the candidates is significant and the event itself is quite significant."



'I've gone off the Liberals'

One resident, who had just cast his vote, told the ABC it was the first time he had not voted for the Liberals.

"I voted independent for the first time ever," he said.

"I've gone off the Liberals or the National Party, you know, they're all over the place.

"And what they did to Malcolm Turnbull here is dead wrong. They're making little mistakes all the time, what are they doing in the big mistakes, we don't know."

Anger lingers over Turnbull ousting, Phelps says

Dr Phelps said there was "no question there's a lingering anger about the removal of Malcolm Turnbull", along with his resignation, which triggered the by-election.

She told media she sought to "set the agenda" for the by-election by talking about "issues that are important to the future of Australia".

"Climate change, what's happening to kids on Nauru, getting them and their families away from Nauru, supporting the independence of the ABC, these are all important issues for the Australian people and they're important to the future of our country," Dr Phelps added.

Asked about the recent backtracking by some Coalition senators who voted yes to a motion by One Nation's Pauline Hanson, that "it's okay to be white" — a white nationalist sentiment — Dr Phelps said "we've seen enough this week of reckless voting".

"If you don't know what the motion is, if it's just a hypothetical, then it would be completely reckless to say I would vote one way or another," Dr Phelps said.

"I want to hear evidence, I want to see the motion, and understand it before I'd be prepared to vote on it."