NI21 leader Basil McCrea has met police and issued a solicitor's letter to stop a disgruntled former PR adviser mentioning him on social media.
Jon SW Rainey released a letter from Mr McCrea's lawyers accusing him of harassing their client.
Mr Rainey has denied that he meant to do any such thing, and Mr McCrea (right) says he accepts his assurance.
"I am glad that he has clarified his position that he wasn't doing that and as far as I am concerned that is the end of the matter.
"I have sent him a solicitor's letter and he has responded," Mr McCrea said.
However, Mr Rainey has refused three clear demands made by Mr McCrea's solicitor Jane Robinson of Saintfield firm Peter Bowles and Co.
Ms Robinson demanded that Mr Rainey remove all references to Basil McCrea and NI21 from his Twitter feed, "agree that you will not post any further tweets in respect of our client either directly or indirectly", and "agree will that you will not encourage or persuade anybody to publish offensive tweets".
She added: "Failure to address our client's reasonable requests shall result in legal proceedings for defamation/protection from harassment being issued against you without further notice." Last night Mr Rainey said: "I have discussed this issue with solicitors over the weekend.
"I am satisfied, as are they, I have not defamed Mr Basil McCrea MLA in any way in any of my social media content.
"I am, however, upset that such a strong advocate of free speech would attempt to silence or obstruct a member of the public engaging in social media activity as directed by his letter attached."
Mr Rainey added that he met Tina McKenzie, the party chairperson, in March to discuss working for NI21 on her campaign to be elected to the European parliament.
He was informed "their resources could not cover" his charges, and since then he has been publicly critical of the party.
Mr Rainey, who lives in Cavan and suffered when the Republic's property bubble burst, has worked with a number of political parties and parted company with them.
They include Fine Gael and the Ulster Unionists, as well as NI21.
On his Facebook page, he describes himself as "a right wing zionist royalist pro-Commonwealth pro-death penalty anti-abortion pro-nuclear unionist".
He adds that, if he was voting in the Northern Ireland elections, it would be for Alliance and the Tories.
He writes "none of the 'Unionist' parties represent my views on equality and personal rights".
NI21 is Northern Ireland's newest political party and supports a moderate pro-Union agenda. Jon Rainey ran a company called The Political Firm which has conducted non-accredited polls. He was part of the NI21 team during the launch of the party last year and held the position of director of communications. He describes that as "an unpaid role which I believe I executed reasonably well".