A new study is urging the federal government to take a critical look at its outsourcing costs if it wants to get serious about spending controls.

The study by the Canadian Centre for Policy Alternatives says the "growing and concentrated nature" of outsourcing has created a shadow public service that is immune to the hiring practices and transparency requirements of the real public service.

The study's author, research associate David Macdonald, says personnel outsourcing costs have risen 79 per cent in five years.

Macdonald says that while federal departments have had their budgets capped, spending on outside consultants has not been touched and exceeds $1 billion annually.

Contractors used to be hired for a week or so to do some filing, he says, but now they are being hired on contract for years at a time.

Four large departments — Public Works and Government Services Canada, National Defence and Canadian Forces, Human Resources and Skills Development, and Public Safety and Emergency Preparedness — comprise half of all federal government outsourcing.

Macdonald says their payrolls increased only nine per cent since 2005-06, but their personnel outsourcing costs exploded, rising 100 per cent.

"Without prompt corrective action, outsourcing costs will continue to soar," Macdonald says. "With the federal government running a significant deficit, it is more important than ever to examine measures that offer potential savings while maintaining services."