The DUP's decision to try to ban a Sinn Féin councillor from a Christmas party has cost the party's nine members of Coleraine Borough Council more than £18,000 (€26,800) in legal fees.
The former DUP mayor of Coleraine, Timothy Deans, supported by his colleagues, decided that Sinn Féin councillor Billy Leonard - a former member of the RUC reserve and Protestant lay preacher - should not attend the function last Christmas.
Mr Leonard, who defected from the SDLP to Sinn Féin and was the Sinn Féin candidate for East Derry in the 2005 Westminster general election, attended the party in any event and also initiated legal proceedings to challenge the ban.
The councillors were given legal advice that they would lose their case when it came to the High Court and eventually agreed that they should meet the £18,600 legal costs incurred by the council during the proceedings.
Mr Deans was also obliged to write a letter of apology to Mr Leonard, admitting he had been ignorant of the law regarding equality matters in local government.
Mr Leonard, who ignored the ban and attended the party, said that "legally, financially and morally, it has been shown to the public that the DUP mayor acted wrongly and stupidly.
"The whole episode uncovered the entire hypocrisy of a DUP mayor utterly failing to see the difference between his civic position and his party position. To have walked into this pathetic situation with arrogance that was no more than crass political stupidity shows what we are up against at local level and what Sinn Féin will take on," he added.
The DUP in Coleraine affected to be unembarrassed and also unapologetic by the cost of trying to prevent Mr Leonard attending the function.
Councillor Adrian McQuillan said he would attempt to issue the ban all over again if given the chance. "There is an Ulster Unionist mayor in place now so I don't think Sinn Féin will be barred from the party this year.
"We paid the money between us - we didn't have to rob the Northern Bank to do it. There was no cost to the ratepayer," he added.
