The decision to tie public service bonuses to federal cuts is a bid to motivate government executives to find savings, a Conservative MP says.

Andrew Saxton, the parliamentary secretary to Treasury Board president Tony Clement, says it's a common tactic to help find cuts.

"It happens in the private sector all the time. If you want to achieve something, you have to motivate people to do it, and that's what we're doing here. We're not going to apologize for asking our senior executives to find ways to save money and operate more efficiently," Saxton told Evan Solomon, host of CBC-TV's Power & Politics.

Clement told the Globe and Mail that 40 per cent of "at risk" pay for senior managers would be tied to their ability to find the $4 billion in permanent savings the government is looking for in the next budget.

NDP finance critic Peggy Nash calls the $4-billion goal arbitrary.

"It's a heck of a way to improve morale in the public sector," she said of linking the bonus pay to cuts.

"What they're doing is incentivizing management to cut the jobs of the people who actually provide the services — scientists and front-line community workers," she said.

Saxton said it's important to ask the top-level civil servants where to make the cuts the government has planned.

"They know how they can save money," Saxton said. "The best people to ask how to save money are the people that are living it every day."

McCallum said the government should delay the cuts because the economy is too weak right now to support public sector cuts.

A Treasury Board spokeswoman says having employees work toward a corporate goal is a best practice in the private sector.

"In July 2011, the Government of Canada made changes to at-risk pay by linking it to the achievement of a corporate commitment. Prior to that, executives received performance pay based primarily on the achievement of individual commitments," Anabel Lindblad said in a statement.

The government has also hired Deloitte Inc. on a $19.8-million contract to offer advice on the cuts. Saxton says the government needs advice from both the private and public sectors.