What's next, as Liberals and Nationals go their own way?

The Liberals and Nationals are going their own way, again.

But like their eight-day split after the May federal election, it could be a brief interregnum, as the question of whether Sussan Ley can hold onto her leadership re-emerges.

Liberal and National MPs are despondent at the Coalition's new low ebb, following the total resignation of Nationals from the frontbench, citing solidarity with three senators who defied the Coalition's formal position on hate laws and voted against them.

On social media, conservative Liberal senator Alex Antic said he had never been as disappointed in politics as he had in the past 24 hours, adding "we must drain the billabong".

Shadow Attorney-General Andrew Wallace said he was "clearly" upset, and that these were difficult times for both parties.

Liberals and Nationals to field separate 'shadow ministries'

For now, both the Liberals and Nationals are looking towards a new carve-up of portfolios — the third reshuffle in eight months.

While the option to simply share around empty portfolios to existing shadow ministers existed when it was just the three Nationals senators departing, the exit of 11 portfolio holders will require a more significant reshaping of Ms Ley's frontbench.

A similar plan never eventuated at the Coalition's first break-up, and this one could also be short-lived.

Ms Ley won the leadership of the Liberals by only a few votes in May, and her entire tenure as leader has been clouded by questions of whether leadership aspirants Angus Taylor and Andrew Hastie could seek to challenge her.

While neither wants to be seen unseating the Liberal Party's first female leader, the second Coalition break-up in less than a year has reignited speculation of a spill when Liberal MPs again gather under one roof in February.

One test for the opposition leader will be recruiting replacements. If doubts grow about Ms Ley's longevity, MPs may be hesitant to tie their flag to her mast.

Meanwhile, the Nationals say they intend to build their own full "ministry" that will develop its own policy positions.

"We will now just apportion within all our MPs different responsibilities and roles, and have spokespeople across an array of areas now, which we currently don't do," deputy leader of the National Party Kevin Hogan said.

Nationals head to the crossbench

The mass migration to the crossbench will not affect votes in the lower house, where Labor holds an outright majority, though it will change the appearance of the chamber and of Question Time — where Nationals MPs will have fewer opportunities to challenge the government as members of the crossbench.

In the Senate, non-government senators have the majority and often unite in order to refer matters for inquiry, order the government to produce documents, or determine proceedings in the chamber — something that will likely continue.

However, it could also give the government another pathway to pass legislation, as Labor could now pass bills with either the support of the Greens, the Liberals or the Nationals plus five other crossbenchers.

Nationals MPs were saying yesterday that they were not seeking to "blow up" the Coalition by defying the formal position on hate laws and were only acting on principle. 

But the tone has since shifted, and National Party leader David Littleproud directly pinned the blame on Ms Ley this morning as he announced the Nationals would divorce from the Liberals.

Whether or not the Nationals meant to destabilise Ms Ley, Liberal MPs have perceived it as meddling.

Angry Liberals say the Nationals should keep out of their affairs, and say they left Ms Ley with no choice but to remove the renegade National shadow ministers who crossed the floor in the Senate.

"The Liberal Party determines who its leader is, and that's the way it should be," Shadow Attorney-General Andrew Wallace told ABC Sunshine Coast.

Mr Wallace said the Nationals' mass resignation was not an outcome the Liberal Party wanted, but that cabinet solidarity had to be complied with or else "you're just a heap of individuals doing your own thing".

It was also a breach of the agreement made by the Nationals when they rejoined the Coalition in May, and promised to honour cabinet solidarity.

Mr Wallace added that it was not lost on him "that the day the Nationals decide to split is the day the country has set aside for mourning those 15 souls who were lost [in the Bondi terror attack]".

Few options for Ley

While Liberal anger is pointed towards the Nationals today, the Liberal and National positions in the polls remain dire.

MPs fear an ascendant One Nation (particularly with some Senate pre-selections on the horizon that could reorder the Liberal ticket), and a bad summer for the government seems not to have materialised as an improvement to the Coalition's position.

Both parties know they cannot be on their own forever if they want to have any chance of winning back government.

Former prime minister Malcolm Turnbull said he was sure the two parties would reunite at some point for exactly that reason.

"The bottom line is this: The Liberal Party, to form government, needs to have the National Party because it needs to have those regional seats. It also needs to win back seats in the city," he told ABC Melbourne.

The former Liberal leader also suggested the disagreement could have been better managed, laying blame on both sides for what he described as a "smouldering wreckage".

Mr Hogan maintained, even as he defended the split, that the Coalition was better together, and he would like to see the parties reunited "as quickly as we can".

He also "very much doubted" a future where the Nationals would instead turn to One Nation, who were seeking to claim National-held seats.

Mr Hogan said, however, that Mr Littleproud had stipulated to Ms Ley that reuniting would require the reinstatement of senators Bridget McKenzie, Susan McDonald and Ross Cadell to the shadow cabinet, which she had refused.

It leaves little option for the besieged leader: either go back on her position and lose standing among Liberal colleagues, or hold to it and lead a diminished opposition that will have fewer resources to prosecute the government.

And even if the Coalition can reunite, it will still have to contend with the same fractures in the centre-right parties that led to today's split, and the same question over how to reclaim the ground lost over two successive elections.