The leader of a party which aimed to break the mould of sectarian politics in Northern Ireland has said he is quitting with his head held high.
NI21 founder Basil McCrea said he had become disillusioned during his period at the Stormont Assembly.
The party was established as an alternative to what it saw as green and orange-tinted politics, and pledged to focus on its modernising vision of bolstering science and innovation and creating a shared Northern Ireland identity.
But the fledgling group imploded over whether to define itself as unionist ahead of the local government and European elections in 2014 and ended up winning only one council seat.
Mr McCrea told the Assembly: “I will leave this place with my head high, with my colours flying, with my dignity intact and with all conviction about what is good for Northern Ireland.”
The Lagan Valley Assembly member has announced that he will not contest the May elections and is seeking a new career.
Mr McCrea and fellow Ulster Unionist John McCallister left the party in 2013 to establish the new group.
However, the eve-of-election feud between the two men the following year wrecked NI21’s chances of electoral success.
At the time there were rumoured to be wider personality differences between the two men as well as the row over designation.
Earlier this month the Assembly Standards Commissioner dismissed all complaints of misconduct made against Mr McCrea.
It cleared him of claims of inappropriate behaviour and sexual misconduct towards his staff.
However, standards committee Assembly members said the manner in which he occasionally treated his staff fell short of the standard they would encourage.
Mr McCrea made no reference to the controversy as he delivered a valedictory speech during the last plenary session of the Assembly’s mandate.
He quoted Winston Churchill and Robert Frost’s The Road Not Taken and said: “I took the road less travelled and that has made all the difference.”
He added: “I am proud of what I achieved, I am proud of what I tried to achieve.”
Mr McCrea represented manufacturers in an influential lobby group before turning to politics.
He was an articulate representative for the Ulster Unionists and said he enjoyed his period working on higher education issues at the Assembly.
He advocated the primacy of science and technology and the arts.
But grassroots supporters of NI21, many of whom had never entered politics before, were left furious by the meltdown over whether to designate as unionist ahead of their inaugural election.
Mr McCallister, an outgoing independent, stood near Mr McCrea as he delivered his own summing up of the Assembly. He failed to mention his former colleague.