Dumped Prime Minister Malcolm Turnbull is heading to New York with wife Lucy for six weeks

Dumped Prime Minister Malcolm Turnbull is heading overseas with wife Lucy for six weeks, leaving his former colleagues to battle for his blue-ribbon seat of Wentworth.

Mr Turnbull's resignation from Parliament on Friday will spark a by-election, which could threaten the government's one-seat majority.

The latest ReachTel poll has the Liberal Party and Labor at 50 per cent each on a two-party preferred basis, in a sign voters could punish the government for knifing Mr Turnbull.

Although the polls suggest Wentworth could fall to Labor for the first time in history, the former prime minister won't be joining the Liberal's campaign to retain the seat.

On Sunday, he and his wife will fly to New York, where the pair own a two-bedroom Manhattan apartment they purchased for $4.5million in 2012.

The Turnbulls own this two-bedroom Manhattan apartment, purchased for $4.5million in 2012

The former prime minister won't be joining the Liberals' campaign to retain his seat

Senior Liberal MPs are said to be fuming Mr Turnbull won't be helping his successor campaign for his old eastern Sydney seat, according to The Daily Telegraph.

The Turnbulls' 1930s art-deco apartment, overlooking Central Park, boasts hardwood floors and decorative fireplaces, while the building has full-time doormen and elevator attendants.

'New York is my second favourite city [after Sydney] and I had been looking at property there for quite a while,' Mrs Turnbull told Fairfax at the time of the purchase.

'We wanted to be close to Lincoln Centre and Columbus Circle, a vibrant part of New York City, close to the subway hub and conveniently located close to midtown and to Central Park.'

The art-deco apartment boasts hardwood floors and decorative fireplaces, while the building (pictured) has full-time doormen and elevator attendants

Mr Turnbull's resignation from Parliament on Friday will spark a by-election in his seat of Wentworth

Meanwhile, business owner and City of Sydney councillor Angela Vithoulkas has joined the race for Mr Turnbull's soon-to-be vacant federal seat.

Ms Vithoulkas on Thursday confirmed she will stand as an independent in the Wentworth by-election, expected to be held in October.

She said voters in the eastern suburbs electorate needed 'stability, continuity and fearlessness', and vowed to bring that as a strong independent.

'I want to rebuild the faith people should have in their community leaders, and make them the priority, not a pawn in party politics,' she said in a statement.

Ms Vithoulkas is among dozens of business owners and landlords planning to file a lawsuit against the NSW government over the embattled Sydney light rail project.

Ms Vithoulkas is planning to file a lawsuit against the NSW government over the embattled Sydney light rail project

She claims the project forced her to close her CBD cafe after 16 years of trade.

Former Business Council of Australia executive director and same-sex marriage campaigner Andrew Bragg is emerging as the frontrunner to replace his friend Mr Turnbull as the Liberal candidate.

Former Australian ambassador to Israel Dave Sharma and former prime minister Tony Abbott's sister Christine Forster are also in the running for preselection, while Labor has preselected local businessman Tim Murray.

Independent Kerryn Phelps, another City of Sydney councillor, is also considering a tilt.