The seat of Warringah, on Sydney’s northern beaches, has never been marginal and has always been held for the conservative side of politics. Nevertheless, it’s likely to be one of the most watched seats in the coming federal campaign because the Labor party, the Greens, and, it seems, a handful of Liberals want to discredit the local MP, former PM Tony Abbott, by driving him out of federal parliament.

Late last year, the Daily Telegraph reported union sources saying that they’d spend hundreds of thousands of dollars supporting independents in seats such as Warringah that Labor couldn’t win. It was reported elsewhere that a small group of climate-warrior millionaires were prepared to put $750,000 into the main anti-Abbott independent’s campaign. Then there’s the green-left activist group GetUp!, with a budget of $9 million a year, that’s made rolling Abbott its main election focus. GetUp! has already organised two 500-plus-attendee campaign meetings, and has promised to door knock all 65,000 Warringah households with stories about how Abbott’s views have made electors feel bad. Last week, GetUp! types were distracting motorists on the Spit Bridge dressed-up as dinosaurs with placards saying that the ‘fossil’ had to go. For months now, there have been anti-Abbott posters appearing around the electorate featuring his allegedly ‘pre-historic’ views on coal, women and global warming.

Even though the main anti-Abbott candidate, ex-skier-turned-family-law-barrister Zali Steggall, has no record of local community service and no particular distinction other than in sport, any local campaign with close to a million dollars of funding, the GetUp! machinery, and Labor and union expertise behind it is truly formidable. Unsurprisingly, there’s already been plenty of barracking from Fairfax and the ABC – with a 7.30 journalist accompaning Steggall in her car to her campaign launch, which the Sun-Herald flagged with its entire front page.

The anti-Abbott pitch is that he’s been there too long, he’s out of touch on same-sex marriage and climate change, and that he has to be removed from the parliament lest he become Opposition leader after the election. For someone who’s supposed to be out-of-date and irrelevant, the broad Left is putting in a Herculean effort to remove him, buoyed by the success of the green-left-masquerading-as-a-disillusioned-small-l-liberal Kerryn Phelps in winning Wentworth, a similarly well-heeled seat across the harbour. If Phelps could overturn the 17 per cent Liberal margin there, the reasoning goes, Abbott’s 12 per cent margin makes him vulnerable as he’s the conservative Liberal that progressive Liberals love to hate.

There’s actually a huge difference between the two contests, quite apart from the fact that a by-election’s ‘protest’ dynamic is always very different from a general election that’s about choosing a government. Malcolm Turnbull hadn’t just resigned his seat in a huff, after losing the prime ministership, but he’d ostentatiously refused to campaign for the Liberal candidate Dave Sharma. Turnbull’s son Alex openly supported the independent.

There has never been as much sympathy for Turnbull north of the harbour as south of it. And he’s worn out much of it with his post-Wentworth antics – such as backing an independent against health minister Greg Hunt – that seem anti-Liberal rather just anti-the conservative faction that’s supposed to have rolled him. Moreover Abbott is not a blow-in newbie but a long-serving local member who does surf patrols, shifts with the local fire brigade and raises millions of dollars for charity with his pollie pedal bike ride; as well as bringing massive benefits to his area such as the $150 million that the Howard government spent preserving the unspoilt headlands of Sydney Harbour.

Sure, Abbott’s part of the Abbott-Turnbull feud that’s cannibalised the current government the way the Rudd-Gillard feud cannibalised the previous one. But unlike Turnbull, Abbott sat quietly on the backbenches in the run up to the previous election, and had been happy to include his rival in the cabinet. Indeed, the six years of Abbott’s leadership were largely devoid of internal ideological divisions. The argument that Turnbull used against Abbott was not that he was too hard-line (he was actually supposed to have lost his economic narrative) but that the polls had turned against him.

Zali Steggall’s backers are playing up her supposedly Liberal credentials. Her grandmother, for instance, was a branch president in the Hunter region; and her husband is the son of a friend of John Howard. Yet her admission that she’d never voted for Tony Abbott meant that she’s never actually voted Liberal in her life at a federal election. Not only was the Howard government too right-wing for her but so was the Turnbull government. And on climate change, she’s so far left that she says Labor’s policy ‘doesn’t go far enough’. She’s denied being the GetUp! candidate, but key figures in her campaign were part of the Phelps campaign or were part of previous left-wing independent campaigns in Warringah.

Years of calumny from internal rivals have certainly damaged Abbott’s reputation. Yet bringing the Liberals back to government in just two terms, stopping the boats, and having a go at long-term structural economic reform in the 2014 budget are historic achievements.  By any criteria, Abbott is a formidable political warrior and his ousting would be a devastating blow to the conservative side of politics. Who else, other than Josh Frydenberg, would be left to rebuild the Liberals in the event of an election defeat, with Scott Morrison discredited, Julie Bishop mistrusted and Peter Dutton likely gone too?

Abbott knows the stakes are high and has declared that Warringah is now a marginal seat. While the independents are trying to make it a referendum on climate change, Abbott argues that the Warringah election is about the government you want: not one that hits you with more tax and thinks that the northern beaches road tunnel should be scrapped.