Malcolm Turnbull has admitted he went into bat for Jane Prentice at her recent preselection – urging her branch in Queensland to keep her as its representative – and was ignored.

The prime minister, who referred to the assistant social services minister as “a friend of mine”, said he believed he had done all he could to boost her chances of preselection for the seat of Ryan, but would not be intervening to insist she was reinstated.

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“I certainly stood up for her,” he told 3AW radio. “I gave her a reference, my representative [Peter Dutton] who went to the meeting voted for her, but he was one out of 370 people at the meeting – overwhelmingly local members of her [branch].

“The members of the Liberal party have got their own minds, as they should. Everyone calls for democracy in political parties. You can’t have it both ways.

“If you say join the Liberal party and have your say in who is going to be your member of parliament, then if your membership makes a choice that you don’t agree with, you can’t then turn around and cancel it out.”

Turnbull again ruled out quotas as a way to increase the number of women within his party, saying it was incompatible with the Liberal party’s values and grassroots foundation.

But the prime minister, who donated $1.75m of his own money to the federal Liberal party campaign at the last election, said his Wentworth branch would be donating to the fund established by Kelly O’Dwyer that aims to increase the number of women within the party.

Jane Prentice loses LNP preselection for Queensland seat of Ryan Read more

O’Dwyer told Guardian Australia she would be donating $50,000 to the Enid Lyons Fighting Fund and would be calling on her cabinet colleagues to match her commitment. Turnbull pledged his branch’s fund.

“That [the fighting fund] shows great initiative and great leadership. My conference, the Liberal party in Sydney, will certainly match that,” he said. “We’ll contribute through the party.”

Prentice lost her spot by about 150 votes in Brisbane’s largest ever Liberal party preselection vote on 12 May, after her former campaign manager Julian Simmonds moved against her.

Prentice and Simmonds had a long-time deal in place for Prentice to hand over her position to him, with the only dispute being when the switch was to occur. Prentice’s camp said she had one more term, while Simmonds’ supporters say her term had already been extended when she ran for the 2016 election.

While Prentice’s Queensland colleagues have spoken out against the move, Turnbull and other senior Liberal members, including Scott Morrison and Simon Birmingham, have ruled out any intervention to reverse the decision.

That has put the spotlight on when interventions are expected to take place to save sitting members who are under pressure from their branches, including Ian Goodenough, who is expected to be saved in his upcoming preselection, as well as Jane Hume and Ann Sudmalis, who are also under threat.

Women make up about 20% of the Liberal party, while its coalition partner, the National party, can only claim 14%. Labor, which has had quotas in place since 1994, is approaching gender parity, with 48% female representation.