An Irish Government official was to attend the council meeting
Two unionists have been elected to the top posts in a County Antrim council despite claims of discrimination from Sinn Fein.
An Irish Government official was due to attend Thursday's mayoral elections at Lisburn City Council after nationalist and republican councillors claimed they were being excluded from positions of authority.
The planned visit had been strongly opposed by unionist councillors.
However, Sinn Fein councillor Paul Butler said the official had backed out from watching the meeting, and said the party felt a "sense of betrayal" about the move.
The Irish Government said it had never made a firm commitment to attend and offered to meet Sinn Fein after the annual general meeting.
Sinn Fein said that was "not good enough".
At the meeting, the Democratic Unionist Party's Cecil Calvert was elected unopposed as the city's new mayor, with Sinn Fein abstaining from the vote.
He is the first DUP mayor for the area in 22 years.
Ulster Unionist William Gardiner Watson was elected as the deputy mayor, after defeating Paul Butler by 21 votes to seven.
Last year, none of Lisburn City Council's seven nationalist councillors was appointed as a committee chair or vice chair, mayor or deputy mayor, a decision which was criticised by the Irish Government.
Earlier on Thursday, Edwin Poots of the Democratic Unionist Party had questioned the intention of the Irish Government to send an observer to the meeting.
"It is unwarranted, unwelcome and unprecedented interference from the Dublin Government in the internal affairs of Lisburn City Council," he said.
But Sinn Fein's Paul Butler said that the council was not being inclusive.
"A system of political apartheid was put in place where ourselves and other
non-unionists were excluded," he said.
"A lot of the outside bodies that the councillors are appointed to - nationalists are not on any of them. "
But unionists said that everyone got a fair deal when the committee chair and mayoral jobs were handed out.
Mr Poots said Mr Butler had turned down the offer of vice-chair of the Strategic Policy Committee last year.
He added: "Non-unionists have held the mayorship of Lisburn for four years in the