The divisions within Australian politics over the Israel-Gaza war were on full display on Monday as senior leaders marked the first anniversary of the 7 October attacks.

The Labor government reaffirmed its unequivocal condemnation of the Hamas-led attacks on southern Israel in which about 1,200 people were killed and 251 were taken hostage.

But Labor also acknowledged the “devastating” loss of civilian lives over the past year of war. The Coalition opposition offered emphatic support of Israel and chided the Labor government for calling for a ceasefire.

“The Coalition stands with our ally Israel – rather than treating her like an adversary,” the opposition leader, Peter Dutton, said.

The Greens said the 7 October attacks “deserve nothing less than our most full condemnation as a community” but went on to condemn the Australian government for “refusing to sanction the extremist Netanyahu government” for the way it carried out its response.

“The very same commitment to compassion, honesty, peace and justice required of us in response to those attacks of Hamas requires us as Greens to call out the war crimes and genocide that is being carried out by the State of Israel right now in Gaza and the rest of the occupied territories and the bombing and invasion of Lebanon,” the party said in a statement.

The independent senator Fatima Payman, who quit the Labor party in July after crossing the floor to support immediate recognition of Palestine as a state, said nothing could justify the killing of civilians.

“As an Australian, as a Muslim and as a humanitarian, the bloodshed of any human being is against the core principles of my identity,” she wrote on social media.

“My thoughts and prayers go out to all who are suffering the loss of loved ones and grieving the genocide.”

The Labor MP Josh Burns said there had been “so much loss over the past year”.

“In Jewish tradition, one life is a whole world. We can and must hold space for every single person who has lost loved ones, whether in Israel, Gaza, Lebanon or across the region.”

Israel has rejected “false and outrageous” allegations of genocide, which are the subject of proceedings initiated by South Africa at the international court of justice.

At least 41,870 Palestinians have been killed and 97,166 wounded in Gaza since Israel launched its military response to the 7 October attacks, the territory’s health authorities said on Sunday, with thousands more likely lost in the rubble.

The prime minister, Anthony Albanese, who is due to attend a Melbourne vigil for the victims of the 7 October attacks on Monday night, said it was important to “pause to reflect on the horrific terrorist atrocity that reverberated around the globe”.

In a video message, Albanese condemned Hamas for “brutality that was inflicted with cold calculation” and expressed sympathy for the families of the hostages experiencing “the agony of waiting and not knowing, or of having the terrible truth confirmed”.

He also reaffirmed “a fundamental principle of our shared humanity: every innocent life matters”.

The foreign affairs minister, Penny Wong, who is due to attend a commemoration at the Israeli embassy on Monday night, said: “The need for peace has never been greater.”

But the Nationals senator Bridget McKenzie told a pro-Israel rally at the front of Parliament House in Canberra on Monday that Australia “should not be calling for ceasefire” every time Israel sought to exercise its right to self-defence.

The former prime minister Tony Abbott told the same rally – organised by Christian organisation Never Again Is Now – that 7 October was “the worst catastrophe to befall Jewish people since the Holocaust” and “a day of infamy”.

“That’s why it is absolutely right that these murderers and the organisations which put them to it, should be utterly destroyed,” Abbott said.

“And sure, we lament the civilian casualties, and we admire the way that Israel has been so incredibly fastidious in trying to avoid them, and we admire the extraordinarily clever and successful way in which the Israeli military and government have fought back.”

The chief prosecutor of the international criminal court, Karim Khan KC, has previously said he had “reasonable grounds to believe” senior Israeli and Hamas leaders were responsible for alleged war crimes and crimes against humanity.

Khan’s allegations against the Israeli prime minister, Benjamin Netanyahu, and the defence minister, Yoav Gallant, include “starvation of civilians as a method of warfare” and “intentionally directing attacks against a civilian population”.

The Israeli government has rejected the allegations in full, arguing the application for arrest warrants amounted to an attempt to deny the country’s right of self-defence.

A pro-Palestine protest is scheduled to be held outside Parliament House in Canberra on Tuesday morning, coinciding with the resumption of parliament.