The Liberal party’s opposition to the Indigenous voice referendum has been labelled a “great betrayal” of the country by one of the key architects of the Uluru Statement from the Heart.

On Wednesday, Liberal Party leader Peter Dutton announced the party would join their Coalition counterparts the Nationals in opposing the voice.

While party backbenchers will be given a free vote on the decision, front benchers who support the proposal will be required to resign or fall back in line.

Cape York Indigenous leader Noel Pearson told ABC radio it was a “sad day” for Australia.

“I couldn’t sleep last night. I was troubled by dreams and the spectre of the Dutton Liberal party’s Judas betrayal of our country.

They’ve had 11 years of power to work on a proper proposal for recognition and the decision they’ve taken yesterday is a very poor outcome of 11 years of power.

I see the leader of the Liberal party, Mr Dutton, as an undertaker preparing the grave to bury Uluru,” he said.

So far Australia has approved 8 out of the 44 proposed referendums across Australia’s constitutional history, none have been approved without bipartisan support.