Travellers were preparing to leave a public car-park at Knock Shrine after Mayo County Council served 12 hours' notice to quit yesterday.
Up to 60 Travelling families have occupied the car-park since last Sunday. The Travellers were described by the Mayo county secretary, Mr Padraig Hughes, as "flyby-night".
Mr Hughes said the right to serve the 12-hour notice had been granted to Mayo County Council at the Western Circuit Court last year, after the council took an action to have a similar convoy of caravans removed following their occupation of the same public car-park over a number of weeks.
If the Travellers ignored the notice, they would be summonsed before the Circuit Court in Mayo forthwith, he said.
"It is our belief that these are not homeless Travellers looking to the council for housing. They have homes elsewhere, and our legal advisers are now serving notice on them to quit within 12 hours. If they fail to do so, they will be in contempt of court."
He added that he presumed the Travellers had arrived at the beginning of the summer pilgrimage season to trade and "make a few bob".
They entered the car-park just moments after the gates had been opened for the pilgrimage season last Sunday evening.
"The fact is they are on council property and are preventing other people parking there, and as a result they are interfering with business in the area," Mr Hughes said.
"We as a council are not anxious to provide accommodation for fly-by-night Travellers coming here with trading purposes in mind. If they wish to trade, they must comply with the law, just as with settled people, and not trespass, which is what they are doing.
"They must first of all have a location, then apply for planning permission and then abide by the same regulations as all other people. We are concerned that there are 60 caravans in a car-park using it for purposes we do not intend it for, and I do not see that any private or public body should feel it has to provide such accommodation," said Mr Hughes.
Residents and traders in Knock were yesterday critical of the council for failing to ensure that the situation, which persisted for a number of weeks last year, did not arise again. A spokesman for the traders said it was not any business that might be being carried out by the Travellers that was causing concern, but their occupation of the car-park, which was obstructing other members of the public from parking there.
One Traveller said they had come to Knock to have a holiday in a holy place. He claimed local people had refused to serve the Travellers in their establishments and said he had a right to stay in the car-park and would do whatever he could to remain there.