Estimates reveal the federal government is spending billions of dollars a year on professional services. (Canadian Press)

The president of a union representing thousands of professionals is slamming the federal government over its increasing use of consultants, saying the practice could lead to weaker services for Canadians.

"It changes subtly at first, because most taxpayers don't understand the importance of the public service until one day the light come on and they're paying a lot more or there's some kind of disaster like with Walkerton," said Gary Corbett, head of the Professional Institute of the Public Service.

"These services that were once in the domain of the public sector have now been privatized and that's really what's happening here."

The union, which is researching the government's use of consultants, said that preliminary findings show that over the past five years, the cost of outsourcing has ballooned by at least 80 per cent. Estimates reveal the government is spending billions of dollars a year on professional services.

"It's a parallel public service if you will that's doing public service functions. It's an astronomical growth in the last number of years," said Corbett.

He said the government can't justify the large increase in consultant services.

"They're talking about the need to reduce the public service, to be efficient in the current economic climate, at the same time costs are going through the roof on these kinds of things like contracting out. It's a philosophical change … just like the corporate agenda."

Professional consultants include lawyers, auditors, writers, procurement experts and information technology gurus.

There are also hundreds of federal public service pensioners coming back and filling in at the highest levels, such as the assistant deputy minister ranks. Baby boomers leaving the government are creating a vacuum at the top and some managers are filling these high-level spots with consultants.

"I've been in environments where there are 80 consultants and 10 staff or 20 staff and we outnumber them and that's a very different experience from when you're the two or three token consultants," said Gordon Martin, a senior analyst and technical architect who is one of the thousands of people who works as a contractor for the government.

Alex Beraskow, who runs a consulting firm specializing in IT and management, said the use of consultants by the government is a huge business.

"It's the single largest market in Canada for professional services. It's what we call a sunrise industry rather than a sunset industry," said Beraskow. Government managers look to private sector consultants because these people work on flexible, short-term projects. They can be hired quickly and are not a liability when it comes to benefits and pensions.

Maurice Chenier is the chief executive officer of the Information Technology Services Branch at Public Works. About a third of the staff in his department are consultants.

"We usually do not hire consultants for something that is a function that takes many months, many years," said Chenier. "This is where we have internal knowledge and we're using public servants."

University of Ottawa Prof. David Zussman noted that contractors are now being tasked with policy development work, something that used to be up to the core public service.

"My great fear is that the public service will get used to using consultants for a lot of work that in my estimation should be done internally. As a former public servant, I'd be very reluctant to give the core activity away to someone else."

Julie Ireton, the 2010 Michener-Deacon Fellow, is investigating issues in the federal public service