Former Indigenous Australians Minister Ken Wyatt has described his choice to prompted by the party's formal opposition to the Voice, as a "hard decision".
Mr Wyatt, the first Aboriginal person to be the Indigenous minister, rejected claims from Opposition Leader Peter Dutton that the body would be an elitist "Canberra voice".
"I had to weigh up my love of the Liberal Party and its values and what it stands for against a stubborn position of not wanting to give Aboriginal people a seat at the table," Wyatt told the ABC's 7.30 program.
"I wanted to fight for the Voice because this is something we've asked for over many decades."
Mr Wyatt resigned last Thursday following Mr Dutton's announcement that his party would actively campaign against the Voice to Parliament.
The former minister said the decision by the opposition leader was a mixture of genuine opposition and political opportunity.
"It's a tough decision to make but you've got to weigh this up against a section of our community who live with gaps in their lives that are so substantial," he said.
"It is about local community designing their regional Voice and then the regional Voice selecting people they want to represent them in Canberra. It's not a Canberra voice. It is not elite. It is people from the grassroots."
Liberals lose Leeser as spokesman
Wyatt's comments came on the same day the Coalition's
As a member of the shadow front bench, Mr Leeser would have been bound to the party's No stance against his personal convictions. Backbenchers are free to have a conscience vote on the issue.
Mr Leeser said he believed the time for a national Voice had come.
"I believe the Voice can help move the dial on Indigenous education, health, housing, safety and economic development," he said, announcing his resignation on Tuesday.
"I believe better policy is made when the people affected by it are consulted."
Mr Dutton said while he and Mr Leeser agreed on the need for regional Indigenous people to be heard, they differed when it came to constitutional change.
He lauded his colleague as a man of strength and character but maintained the Liberal Party would continue their stated preference for local and regional Voices.
"We want to listen to those people in the communities to get the best possible outcome for them," said Dutton.
"Julian had a view about the Voice being enshrined in the constitution. He is at odds with the overwhelming majority of the Liberal party room."
Burney welcomes 'Yes' defections
Indigenous Australians Minister Linda Burney welcomed the news, saying Mr Leeser had joined a growing chorus of Liberals who support the Voice.
"Julian Leeser has shown strength in putting his principles ahead of politics," she said.
"Aboriginal and Torres Strait Islander people have extended a generous invitation to all Australians to walk together to a better future."
Senior minister Penny Wong said she expected more Liberals to break ranks and support the 'yes' campaign against Mr Dutton's "partisan narrow position".
