The service was recently slated for consistently failing to meet its targets.
Speaking to BBC Radio Ulster, Mr Poots was asked why no one at the Planning Service lost his or her job as a result of the report.
"Even when there is gross incompetence, it is very difficult to sack people in the Civil Service," he said.
-- Advertisement --
The Minister said that even when he had too many civil servants working in his Department, instead of making them redundant, he was forced to redeploy them to other areas.
Speaking about the realities of terminating the employment of incompetent staff, he said: "I think you have to be particularly incompetent to be sacked in the Civil Service."
According to Mr Poots, the situation had arisen through "various deals" negotiated by trade unions over the years.
However, Brian Campfield of the trade union Nipsa rounded on Mr Poots' remarks, describing them as "outrageous".
Mr Campfield said there would be a "strong sense of outrage" among civil servants as a result.
The Environment Minister also confirmed that the Public Accounts Committee's report on the performance of the Planning Service "doesn't make good reading" and said he was currently working on legislation that would "totally change" the system.
(NS/BMcC)
