NI21 row: Tina McKenzie devastated by party turmoil
It will be difficult for Basil McCrea and John McCallister to remain as leader and deputy leader of NI21, its European candidate has said.
Tina McKenzie was speaking after Mr McCrea confirmed he is facing claims of inappropriate sexual activity, which he denies.
The falling out arose after the party re-designated as 'other' rather than 'unionist'.
Mr McCallister alleged it was a bid to derail an investigation he instigated.
In an interview with the BBC, Ms McKenzie, who resigned from the party executive on Thursday night, said she was "absolutely devastated" by the events.
"I have to say I'm seriously burned from politics and I'm very hurt and shocked and devastated," she said.
"I think Basil needs to have a fair process. I think that's important.
"I'm just devastated that all the work up to now has been ruined."
Earlier, Mr McCrea told BBC Radio's Good Morning Ulster that he had done nothing wrong.
He said the allegations were only brought to his attention the previous day.
"At first reading of them, I can say that I deny them, so on that basis I'm not going any further on the description," he said.
"That's obviously an issue that I'm going to have to deal with and one of the things I'm looking at is how best to deal with the issues."
Mr McCallister said a public rift within the party emerged because he instigated an external investigation into rumours relating to Mr McCrea.
He apologised to NI21's supporters for the current turmoil.
NI21 was set up by MLAs Basil McCrea and John McCallister, after they quit the Ulster Unionist Party in 2013.
On Wednesday, Mr McCallister described the party's decision to drop its unionist designation as "crazy" and "dysfunctional".
He alleged the move two days before the election was aimed at trying to force him to quit his post so that he could no longer deal with the external investigation.
Mr McCrea has said he would respond if anyone brought any complaints to his attention.
NI21 candidate for Lisburn and Castlereagh Adam Murray said the past 48 hours had been "heart wrenching".
"This was about a real passion for Northern Ireland for change and reform," he said.
"We poured our heart and soul into this. We knew there would be problems, but to think it would come from the top levels of our own party - we never thought this."