Federal Finance Minister Jim Flaherty stood firmly behind his decision to tax income trusts Tuesday, saying they are already costing governments more than $1 billion a year in lost revenue. 

"I have no intention of altering the substance of the government's decision," Flaherty told hearings into the trust issue being held by the Commons finance committee in Ottawa. 

'I have no intention of altering the substance of the government's decision.'—Finance Minister Jim Flaherty

Flaherty, who was the first witness, said trusts are costing the federal and provincial treasuries more than $1 billion a year in lost tax revenue. He said his estimate last fall that trusts would cost Ottawa $500 million in 2006 was "conservative."

During remarks to the finance committee, Flaherty said that $500-million figure didn't include future conversions — BCE and Telus have since cancelled plans to become trusts — or provincial tax losses.

The minister said Alberta has since indicated that it was losing $450 million a year from trusts and Quebec has estimated the province would have lost $150 million annually if the conversions of "certain large corporations" had gone ahead.

Many corporations have cited tax reasons for their decision to convert to income trusts. Trusts do not directly pay corporate tax. 

Liberal finance critic John McCallum, who asked Flaherty if his department had even studied the impact of a trust tax on investors, said the Finance Department's numbers were "all over the map."

Trust industry disputes figures

Flaherty's figures were also challenged by the Canadian Association of Income Funds, with the group's president George Kesteven calling the government's tax leakage figures "grossly exaggerated" and adding that the numbers keep changing.

"To date, no clear, credible or consistent data has been released by the Department of Finance to prove its claim," he told the committee. "The reality is that there is no tax leakage."

But Flaherty rejected the argument from the industry that trusts don't cause any real tax loss because more tax revenue will eventually come in when RRSP investors or pension plan members start drawing income.

"Think of what you are being told: give income trusts a definite tax break now but get it back sometime in the future," he said. "I cannot and will not fund today’s programs from tomorrow’s revenues."

Flaherty rejected suggestions that have come from some Bloc Québécois and Liberal MPs to extend the tax-free moratorium on existing trusts from four years to 10 years.  

"A longer tax holiday period for trusts would just mean tax unfairness for a longer period of time."

He also rejected calls to exempt oil and gas income trusts from his new tax policy.

"It would be a mistake to carve out the energy sector," Flaherty said.

Flaherty's Halloween evening announcement last year sent shock waves through the income trust community. His decision to impose a tax on existing trusts as of 2011 reversed an earlier campaign pledge to leave them untaxed. Many trust investors say that switch cost their retirement accounts thousands of dollars.

Canadians hurt: group

The Canadian Association of Income Trust Investors says 2.5 million Canadians were hurt by the government's tax change. 

"Do we wish to lose the only investment vehicle that has any hope of providing retired Canadians with the ability to maintain their retirement lifestyle after they no longer receive employment income?" association president Brent Fullard asked committee members.

Flaherty said it was "regrettable" that income trust investors suffered losses following his announcement, but he had to change the policy.

"Although it was a very difficult decision, it was an absolutely necessary decision for the country and for future generations of Canadians, our children and grandchildren," he said.

The finance minister said the tax revenue drain from income trusts could have derailed future tax cuts for Canadians.

"Without giving anything away, I can tell you that, had this government not acted on income trusts, any plans for further tax reductions in the next budget would be at risk."

The hearings continue on Thursday, when Bank of Canada governor David Dodge will be among the witnesses appearing before the committee.