When Howard was himself in the political wilderness in 1993, having lost his party's leadership, he called Tony Abbott and told him to run for Warringah.

Abbott was the head of Australians for a Constitutional Monarchy and making great progress in the case against what he had labelled "Keating's republic".

The seat of Warringah on Sydney's northern beaches had just become vacant and a moderate Liberal, Sydney solicitor Kevin McCann, was the favourite to win it.

Abbott, who was this week criticised for his politicised statement on the death of Bob Hawke, was blooded in the Marxist madness of 1970s Sydney University student politics. He gave an impassioned pre-selection speech about "reclaiming our political culture and helping Australia to achieve the greatness that we all know is within our grasp".

He won the party's endorsement by 16 votes. Later, he told reporters he looked forward to being "a junkyard dog savaging the other side".

Fast forward to 2015, when Abbott lost the prime ministership to long-time rival Malcolm Turnbull. The Sydney Morning Herald and The Age understands Abbott was offered several jobs outside politics, including an academic position at his alma mater, Oxford University, and a business position in Australia. Several corporate and not-for-profit boards were interested in recruiting him.

Abbott has faced many foes in his political life, which started well before he entered Parliament in 1994 aged 37.

But none has been quite like independent Zali Steggall, a former Olympic skier turned barrister who is campaigning on a platform of climate change action.

His rhetoric is robust, hers is measured. He is passionate, she is calm. She positions herself as the future, Abbott stands on his record.

Despite her opponents' attempts to paint Steggall as a puppet for GetUp, the Greens and/or Labor, Steggall is the preferred candidate of a genuine groundswell of grassroots activism in Warringah.

Several local groups, such as Vote Tony Out and North Shore Environmental Stewards, had been active in the electorate well before Steggall decided to run. They reject their local MP's stance on climate action, his social conservatism and what they say is his wrecking of the Liberal Party.

Steggall enjoys the support of this loose coalition and the tacit support of progressive activist group GetUp, which recommends voting for her or fellow independent Susan Moylan Coombs.

Abbott and his campaign assert Steggall has GetUp's backing. She says she has no formal or financial links with the group, which sent 600 orange-shirted volunteers into the electorate for the campaign.

Meanwhile, Advance Australia has campaigned strongly against Stegall. One of the men behind the conservative activist group is former ABC chairman Maurice Newman, who worked for Abbott during his prime ministership, but Abbott's campaign says it is unconnected to Advance Australia.

While Steggall's campaign has garnered maximum publicity, much of it favourable, Abbott's team has run a tightly controlled local campaign with little formal contact with major media outlets.

In predicting a result in Warringah, there is the data and there is the mood, which seems split down the middle, with strong views on both sides.

Of the data, we have little that is reliable - a recent GetUp poll of 805 voters had Abbott trailing Steggall 44-56 per cent.

If Abbott wins, his mission is clear. He has always been on a mission, since first winning the presidency of the Sydney University student body in 1978.

Recently, Abbott has pointed to US presidential hopeful Joe Biden as an indication of how much political fight he has left in him.

Biden is 76. Abbott is only 61.