Treasury Board president Tony Clement defended a plan to introduce a new public sector performance review system, saying poor performing workers are dragging down morale in the federal public service.

"When you looks at the statistics, underperformers are not exiting the system, they continue to be employed by the public service," Clement told Robyn Bresnahan on Ottawa Morning Thursday.

"When you have a dismissal rate of 0.06 per cent, it means there are more public servants, unfortunately, dying at their desks rather than those being dismissed for underperforming," Clement said.

On Tuesday, Clement introduced the system, which is aimed at boosting productivity and efficiency while weeding out workers who don't make the grade.

The review system includes annual performance objectives for all employees, mid-year evaluations and annual written assessments. It will offer plans for improving performance with clear timelines for employees to shape up.

The performance reviews are slated to start in April 2014.

Clement said public sector workers are tired of bearing added workloads because of colleagues that are not pulling their weight.

"It affects public servants.  It affects their morale.  They are working hard for Canada and Canadians and at the workstation next to them there is someone trolling the internet for six, seven eight hours a day. So this is an issue, this is a problem that affects morale," said Clement.

Public servants CBC spoke with Wednesday said they agree there should be consequences for poor performance and that those consequences should include dismissal.

But labour lawyer Chris Rootham says trying to meet the dismissal rate of the private sector — above 5 per cent — is problematic for the government and would likely come with a cost.

"If they legitimately go down this road and try to fire five per cent of the public service for poor performance, they're not going to win every case and they'll end up paying back pay or settle a bunch of them," said Rootham.

Public Service Alliance of Canada national executive vice-president Chris Aylward said many departments already have performance review systems in place and said the real issue is that managers are not properly trained to execute them.

He said that makes the process open to abuse.

"I'm the manager and I really don't know how this process works and I really haven't been trained on how this process is supposed to work and I simply don't like you. Guess what?  You are not going to get a very good rating," said Aylward.

"Especially if I know that the lowest person is going to be out the door. So that's the worst case scenario we can see and we're very concerned about that," said Aylward.