The Ulster Democratic Party has called for the resignation of the Parades Commission's chairman, Mr Tony Holland, after the commission mistakenly passed on personal details of 39 loyalist parade organisers to Sinn Fein.
The Parades Commission yesterday apologised for the error, which it described as a "completely genuine mistake which we very much regret", but said Mr Holland had no intention of resigning. "We have resolved to put procedures in place to make sure that it does not happen again," a spokesman added.
The names and addresses of the secretaries of 39 loyalist bands taking part in a parade in Maghera, Co Derry, last Friday were faxed from the commission's headquarters in Belfast to the Sinn Fein mid-Ulster MLA, Mr John Kelly, after he expressed concern about some of the participating bands.
The RUC visited the individuals on the list to warn them of the incident after a commission member spotted the mistake and reported it to the police.
The UDP leader, Mr Gary McMichael, yesterday said he was "deeply disturbed" by what he described as a "blatant breach of confidentiality" and called for Mr Holland to resign.
"This is a very serious matter which could have profound consequences and implications for the future of the Parades Commission.
"What confidence could any parades' organiser have in providing personal information if he doesn't know where it is going to go next?" Mr McMichael asked, adding he would raise the matter with the Northern Secretary, Mr Peter Mandelson, and the RUC Chief Constable, Sir Ronnie Flanagan.
He also recommended that the band secretaries concerned seek advice on taking legal action against the Parades Commission.
Mr Kelly said the information went no further than himself and accused the RUC of putting an "unacceptable spin" on the incident.
"The reason for requesting the names of the bands was to ensure that no band which had contravened the commission in other areas like Harryville, Bellaghy or the Garvaghy Road would be taking part (in the Maghera parade). I tore up the list of names in deference to the Parades Commission's apologies and concerns over the mistake."