The federal Coalition was imploding on Wednesday night, with all Nationals frontbenchers, including leader David Littleproud, quitting the shadow ministry.

They were retaliating against Opposition Leader Sussan Ley’s insistence three Nationals senators must resign for defying shadow cabinet solidarity.

The Nationals ratified the mass walkout in a special party hook up at 6pm. This followed Ley accepting the resignation of the trio – Bridget McKenzie, Ross Cadell and Susan McDonald – who voted, in accordance with their party’s decision, against the government’s hate crime bill, which passed with Liberal support on Tuesday night.

The chaos deepened further when Ley declined to accept the latest batch of resignations.

As she desperately tries to hold the disintegrating opposition together, she said in a 9pm statement:

This evening, I spoke with Leader of the Nationals, David Littleproud, and strongly urged him not to walk away from the Coalition.

I have received additional offers of resignation from National Party Shadow Ministers, which I and my Liberal Leadership Group have determined are unnecessary.

The Liberal Party supports the Coalition arrangements because they deliver the most effective political alliance for good government. I note that in David’s letter, he has not indicated that the Nationals are leaving the Coalition.

No permanent changes will be made to the Shadow Ministry at this time, giving the National Party time to reconsider these offers of resignation.

The crisis plunges Ley’s leadership into fresh turmoil, and is also putting Littleproud under pressure.

While the resignations do not automatically break the Coalition, its future appears untenable in the present circumstances. Ley sent Littleproud a message on Wednesday evening, asking him to pass it on to Nationals colleagues, in which she said maintaining a strong and functional Coalition “is in the national interest”.

Early Wednesday, Littleproud warned Ley of the walkout if the Senate trio was forced off the frontbench.

The Nationals had put the Liberal leader in a diabolical position. The party’s Senate frontbenchers had defied the principle of shadow cabinet solidarity, and convention would indicate they should resign or be sacked. As Cadell told Sky early Wednesday, “I understand if you do the crime you take the time”.

But the question for Ley was: should she press the convention, or let the “crime” go unpunished to avoid a blow up?

To turn a blind eye, however, would be seen as weakness and further harm her fragile leadership. To let the Nationals get away with their defiance would be interpreted as a dramatic case of the tail wagging the dog.

Liberals, who are now getting blowback for voting for the hate crime legislation, would have been infuriated if the Nationals had been shown lenience.

Former Liberal prime minister John Howard backed Ley, telling The Australian, “She had no choice. She behaved absolutely correctly.”

After hours of public silence in which she consulted with her senior colleagues, Ley issued a statement just before 3pm, indicating the three Nationals would pay the price for their action.

“Shadow cabinet solidarity is not optional. It is the foundation of serious opposition and credible government,” she said.

She said shadow cabinet had on Sunday night examined the government’s hate crime legislation. “The unanimous shadow cabinet decision was to negotiate specific fixes with the government and having secured those amendments, members of the shadow cabinet were bound not to vote against the legislation.”

Ley said that when the Coalition re-formed after last year’s brief split, “the foundational principle underpinning that agreement was a commitment to shadow cabinet solidarity”.

She said she’d made it clear on Tuesday to Littleproud “that members of the shadow cabinet could not vote against the shadow cabinet position”.

Littleproud understood action was now required, she said.

But a letter Littleproud sent Ley early Wednesday made it clear the Nationals’ leader disputed her version of events.

He wrote that there was “also a conventíon of shadow cabinet that a final bill position must be approved by shadow cabinet”.

“This did not take place for this bill, nor was the position presented to the joint party room,” he said.

Littleproud wrote that, “If these [three] resignations are accepted, the entire National Party ministry will resign to take collective responsibility.

"Opposing this bill was a party room decision. The entire National Party shadow ministry is equally bound.”

In her statement Ley said the three senators had offered their resignations from the shadow cabinet, “as is appropriate, and I have accepted them”.

“All three Senators have written to me confirming that they ‘remain ready to continue serving the Coalition in whatever capacity you consider appropriate,’” and she’d asked them to continue serving “in the Coalition team”, outside the frontbench.

She’d also asked Littleproud to nominate replacements.

Last year, Ley was seen as emerging well in her post-election tussle with the Nationals, even though Littleproud extracted concessions.

Prime Minister Anthony Albanese, who a week ago had been on the defensive over his legislation, has now had passed much (albeit not all) of what he initially wanted, and had the additional advantage of seeing the opposition thrown into chaos. The political wheel can turn very fast.