The Liberal Party and the Coalition now stand on the edge of the electoral abyss.

Political gravity drags at their toes, whistling a final ruin in just over six months' time, perhaps sooner.

The Wentworth by-election result is a dreadful and humiliating slap at the Liberals.

Worse for Scott Morrison, it looks very much like a presage of a much nastier blow next year at the general election. The Prime Minister must be wondering if he's caught a hospital pass in August's madness.

The swing against the Liberals is far more venomous than anyone could have predicted a few short weeks ago.

In fact, it is historic in proportions; a shocking repudiation from Liberal and non-Liberal voters alike of the merry-go-round of leadership change that's so polluted politics of both persuasions.

The transactional cost of the leadership switch from Malcolm Turnbull is set to be a tumbling of the Coalition into minority government. This is a very big price to pay.

And Liberal candidate Dave Sharma falls victim to the worst case of political karma seen in Australian electoral history.

Sorry, this video has expired Kerryn Phelps claims victory in Wentworth by-election

Of small comfort to Mr Sharma, a would-be parliamentarian of rare quality, is that he was beaten by a high-calibre opponent gifted a vengeful breeze.

Kerryn Phelps has been a federal politician 30 years in the making.

She's the dream candidate who's been chased by Labor and Liberal parties over the years; an eloquent cleanskin with a just-add-water political persona that oozes the trust and authority so lacking in the place she's poised to become tenant.

The Phelps-Sharma face-off may well be one to watch in May 2019 but it's important to properly digest the nature of Saturday's result.

Wentworth rewrites the record books, with an 18 per cent swing against the Liberal Party on a two-party-preferred basis. This could narrow as more postal votes come in.

Sorry, this video has expired Scott Morrison says the defeat "is on us, the Liberals, not on Dave Sharma"

Before Saturday night, the biggest 2PP swing recorded in by-elections since 1949 was in 1995 when the Liberals snatched the seat of Canberra from the Keating Labor Government with a 16.1 per cent swing (there was a 23 per cent swing in 1992 when independent Phil Cleary took Wills, vacated by ex-Labor PM Bob Hawke, but Cleary was later disqualified by the High Court and the result voided).

The second biggest swing was 14.6 per cent in 1975 against the Whitlam Labor Government in the seat of Bass.

The Bass and Canberra by-election results both proved to be portents of a change of Government a few months later. Many in the Coalition will now feel this is also their fate.

Wentworth has had a 117-year continuous association with the conservatives. It is now in the hands of a change agent who played a big role in the campaign to legalise same-sex marriage. She now vows to campaign on refugees, climate change and better resourcing of the ABC.

Phelps' likely win not only loosens the Government's grip on the House of Representatives but may imperil it further, leaving open the possibility of supporting a referral on Peter Dutton's eligibility to the High Court.

Independent Kerryn Phelps is a dream candidate who oozes trust and authority. ( AAP: Chris Pavlich )

For the Morrison Government, the Wentworth result provides instruction in several ways.

First, and most immediate, the Government must rescue a sense of calm from the mayhem, if anything to prevent tripping into an early election.

For the past week — a week of sheer panic — the Government claimed that a Phelps win on Saturday would rain chaos on Parliament and threaten the very stability of Government.

Now that such an eventuality has arrived, that message that will have to be quickly dispatched. The notion of instability is no longer something to foster, but something to smother.

Morrison and his senior lieutenants have no option but to cast minority government as an annoyance, not a cancer.

Establishing close communication and workable relationships with the crossbench is essential. Morrison knows this and is already active on this front.

Ousting Malcolm Turnbull is set to cost the Coalition majority government. ( ABC News: Matt Roberts )

But the Wentworth result risks further corroding the cornices of the Liberal Party's broad church.

That church has been in undeclared sectarian war since Tony Abbott was sacked as its deacon three years ago.

Scott Morrison, whose conservative instinct is checked by his marketing expertise, faces a partyroom with unresolved differences on energy, climate policy and religious freedom. Shepherding colleagues through those topics will be difficult if discipline isn't maintained, especially when the views of many Liberal MPs run counter to the more centrist politics that permeated Phelps' win in Wentworth.

Morrison has already proved himself fleet-flooted in the face of policy challenges. His vow to end discrimination of gay students in religious schools was a swift response to community sentiment unlocked by the Ruddock review on religious freedoms.

But the PM's foreign policy adventurism last week showed the perils of acting without due consideration.

On the international stage, Australia is yet to see the full price for Morrison's decision to up-end 70 years of bipartisan foreign policy by opening up a discussion about whether Australia should shift its Israel embassy to Jerusalem from Tel Aviv.

At best, this was a courageous stance honestly aimed at enhancing the Middle East peace process.

At worst, Liberals say, it was dangerous and cynically-timed freelancing with insufficient regard to Australia's most pressing regional priorities.

Whatever it was, it was without the imprimatur of considered, expert analysis of the national interest.

Some Liberals believe Morrison would be wise to leave Middle East meddling well alone.

But those close to Morrison say he won't leave anything unturned in pursuit of what appears to be a more distant victory against Bill Shorten.

While this is admirable, it is also the case that everything eventually has a price.