The Canadian Taxpayers Federation isn't impressed with the federal government's fiscal management — even though federation alumni hold senior roles in the government.

The Canadian Taxpayers Federation estimates Canada's national deficit will top $500 billion on Sunday. (Fred Chartrand/Canadian Press)

Prime Minister Stephen Harper's new director of communications is the federation's past-president, John Williamson. Immigration Minister Jason Kenney has also served as the organization's head.

But the current federal director, Kevin Gaudet, accuses Harper's government of committing "fiscal child abuse."

Gaudet told a news conference in Ottawa on Wednesday that, by his calculations, the national debt will top $500 billion on Sunday night, at 10:56:53 p.m. ET to be precise.

"This deficit spending, the borrowing today to pay for the services of today will have to be paid for by the taxpayers of tomorrow," he said.

Gaudet also isn't buying the excuse that the fragile state of the economy justifies enormous deficit spending.

"[There's] an assumption by some people that increased government spending actually causes improvements in the economy, and there's no evidence of that," he said.

Gaudet said the government needs to act now to rein in spending — and start cutting — to get the books back in balance.