A look at the federal seat of Bennelong

HISTORY OF THE BENNELONG ELECTORATE

* Covers 60sq/km on Sydney's lower north shore.

* 1974-2007: Held by former prime minister John Howard until he was defeated by Labor candidate and former ABC journalist Maxine McKew.

* 2007-2010: McKew lasted only one term after being challenged by Liberal candidate and former tennis professional John Alexander. He won the seat after swing of 4.5%.

* 2010-2018: Alexander was forced to step down in 2017 after getting caught up in parliament's dual-citizenship crisis. He renounced his British citizenship to run against against star Labor candidate and former NSW Premier Kristina Keneally in a by-election. He held on despite a swing of more than five per cent to Labor.

WHO IS BRIAN OWLER?

* Labor's high-profile candidate.

* Neurosurgeon working at Westmead Children's Hospital, Westmead Private, Sydney Adventist Hospital at Wahroonga and Norwest Private Hospital.

* The associate professor was president of the Australian Medical Association from 2014 to 2016 and previously president of the AMA in NSW.

* He has been an advocate for pool and road safety, having worked on NSW's "Don't Rush" advertising campaign targeted at reducing speed-related road accidents.

WHO IS JOHN ALEXANDER?

* Incumbent Liberal MP.

* A tennis champion whose career spanned the 1960s to the 1980s. He claimed seven singles titles and 27 doubles titles.

* Headed Tennis Australia's player development and was coach of the Federation Cup team.

* Has an interest in housing affordability, being among Liberal MPs to have urged the government to rethink its opposition to changes to negative gearing.