Public confidence in the Northern Ireland planning service has plummeted by more than 50% in the last decade, a damning report revealed today.

While customer satisfaction rates have dropped from 76% to only 32% in the period since 1998, the cost of processing each application has risen by almost two thirds in the last five years alone.

And though costs have increased the Planning Service has consistently failed to meet many of its main business goals, according to the Audit Office probe.

Comptroller and auditor general Kieran Donnelly said the target date of 2005 to provide up-to-date development plans to cover the entire Northern Ireland had still not been achieved - and was not expected for another 16 months.

He said the objective of establishing a full framework of Planning Policy Statements (PPS) - also scheduled for 2005 - could yet be five years away.

"In seeking to plan and manage development, the agency (planners) has established a number of targets for its main business areas over recent years," he said.

"It has consistently failed to meet a number of these targets."

Last year the service's gross expenditure was £42 million, with an income of £17.7 million - mostly from planning fees.

Mr Donnelly noted a number of factors have influenced planners' performance in recent years.

Among them was the pre-recession property boom, which saw the number of applications rise by 20,000 to 36,000 between 1996 and 2006. This contributed to a major backlog in the system.

He also highlighted the extent to which the service was reliant on other public bodies to process decisions and that the average time taken to complete these consultations was 25 weeks.

The auditor general acknowledged that the service has introduced a number of initiatives to improve its service delivery.