The DUP and Sinn Féin have united in opposition to new-style cross-Border initiative by police.
Both parties dismissed as "a stunt" the PSNI's use of two horses borrowed from the Garda for use in Belfast.
Two PSNI officers have completed training in mounted patrols in Dublin in preparation for a two-day experiment in loyalist east Belfast, thus angering the DUP. A photo-shoot involving a mounted patrol on the Falls Road yesterday later provoked condemnation from Sinn Féin.
One caller to a BBC Radio Ulster phone-in referred pointedly to the PSNI's 50-50 recruitment policy and asked if the horses were drawn from both Catholic and Protestant communities.
Councillor Jimmy Spratt, who fought the Westminster election last year in East Belfast for the DUP, is sharply critical of the idea. "It is a two-day stunt. I cannot describe it as other than that." Mr Spratt is also chairman of the local District Policing Partnership which advises the PSNI locally on community affairs.
"I was absolutely appalled and, indeed, other members of the district police partnership were also appalled at the police even suggesting such a stunt," he added. He called the experience a "ridiculous initiative".
Sinn Féin's Fra McCann accused the PSNI of deliberately disrupting life on the Falls Road in order to engage in a cheap publicity stunt. "Today the PSNI paraded down a section of the Falls Road on the back of two horses accompanied by the usual media pack," he said.
"However to facilitate this publicity stunt, in addition to the horses which we are told have been borrowed for the occasion from the guards, there was a significant armed PSNI presence both on foot and in patrol vehicles.
"Hugh Orde would need to catch himself on. This type of stunt does not impress anybody in areas like west Belfast. In fact if anything it causes even more annoyance, with local people's lives disrupted further by an unnecessary PSNI presence in their community."
Further mounted patrols are planned. Two horses from the Garda's mounted unit will be brought North over the months ahead for up to a week at a time.
Mounted patrols were resumed in Northern Ireland in 2004 for the first time in 80 years.
Assistant Chief Constable Roy Toner said the police service was always examining fresh ways to tackle crime and provide highly-visible patrolling.
"There is evidence that mounted patrols, if properly tasked and deployed, can achieve positive results in crime reduction and detection," he said.
Some 17 British police forces have mounted units and the Garda has 16 horses available for patrols.
"We are very grateful to the Garda for their support and are looking forward to the opportunity of assessing the benefits for our service," Mr Toner added.