The decision by NI21 deputy leader John McCallister to walk away from the party spells the end for what many hoped would be a new brand of politics here.
It was launched in a blaze of publicity at the Mac in Belfast little more than a year ago, promising to be a modern liberal party which would appeal more to young people and the professional classes than the existing parties.
Mr McCallister and Basil McCrea, the founding members of the party, were disillusioned with traditional unionism as espoused by the Ulster Unionist Party and, at first, it seemed they could break the mould. But it was personal disagreements and fall-out which has led to the party's likely demise.
A rump may continue but the glitter has been tarnished beyond restoration after internal rows over how the party should be designated at Stormont and allegations of inappropriate sexual behaviour directed at Mr McCrea, claims which he strongly denies.
This newspaper has consistently argued that a multiplicity of parties in Northern Ireland is good for our fledgling democracy. It is clear that the electorate, particularly young people, are becoming more and more disillusioned with the traditional orange and green politics as exemplified by the DUP and Sinn Fein, the dominant local parties.
Of course it is not easy to launch a new party, no matter what its stated aims, and it is particularly difficult to break the mould in Northern Ireland as others have found before.
And NI21, for all its publicity, seemed to be more shadow than substance. Its most consistent message was 'we are new and not like the other parties'. But voters are not naive.
They can quickly identify when egos run ahead of policy and that is what appears to have happened with NI21.
And if party members – who should be its most dedicated followers – cannot agree, then why should the public give their allegiance?