One in five shop and office premises in the country’s large towns are empty and becoming magnets for litter and dumping, a survey by anti-litter campaigners has found.
The Irish Business Against Litter alliance said the problem was a growing concern and called for it to be tackled by aggressive political initiatives such as compulsory purchase orders.
IBAL chairman Tom Cavanagh said the issue needed to be systematically tackled with a person in each local authority allocated responsibility for saving their town centre.
"It is not just the clean environment that is at stake — these premises are part of the very lifeblood of the town," said Dr Kavanagh. "Also, visitors aren’t interested in out-of-town retail parks — vibrant town centres are an essential part of our tourist product."
The survey, carried out by An Taisce, found an average vacancy rate among commercial properties of 20% with the proportion growing to 33% in some towns.
However, that black mark on the country’s streets comes against a general improvement, with 83% of the 42 large towns and cities surveyed declared to be as clean or cleaner than their European counterparts.
For the first time since IBAL surveys began 18 years ago, Dublin city centre has been declared clean to European norms, although the capital still suffers from black spots such as the north inner city, described as being "in a terrible state", and by the area around the airport.
Top of the litter-free league are the towns of Cavan, Kilkenny, and Tramore, one of which will be named the cleanest town in Ireland at an awards ceremony later today.
The rest of the top 10 in descending order are Clonmel, Waterford City, Wexford, Killarney, Tullamore, Tralee, and Longford.
The worst performers were Castlebar, Portlaoise, Tipperary, Mullingar, and Tallaght, which were all ranked as moderately littered.
Cork City ranked 35 in the list, just making the cut in the clean to European norms category, but the Shandon/Blackpool area made it to the number 20 spot.
Across the country, public parks, approach roads, and recycling centres were most likely to let down the appearance of towns and cities. Some 62% of recycling areas were found to be littered and one in Castlebar was labelled "shocking".
Sweet papers, cigarette butts, fast food packaging, and chewing gum were the most common forms of litter found, and Dr Kavanagh criticised the Government for failing to take the gum lobby to task.
"Our Government is failing to act for the common good by protecting the profits of the gum industry over the environment in which people live," he said.
Environment Minister Phil Hogan rejected the criticism, saying he had secured agreement with the chewing gum industry to invest €9.6m up to the end of this year in advertisements and public awareness campaigns urging the correct disposal of gum.
He said the investment showed a "genuine commitment by industry to finding a solution to improper gum disposal".