Trade Minister Ed Fast says he won't release internal government documents that may predict potential soaring drug costs for Canadians under the free trade agreement with Europe.

The New Democrats challenged the minister to release the documents during testimony today before the House of Commons trade committee.

NDP trade critic Don Davies says Canadians have a right to this information so they can evaluate the deal, which was agreed to in principle by Canada and the European Union last month.

Fast says the government will not provide the public with information that is "speculative."

'We are not going to provide you, or the public with information that is speculative in nature. The information we've been provided is speculative'- Trade Minister Ed Fast

A report last month by two university researchers estimated the cost to Canadians from delaying introduction of cheaper generic medicines will likely range between $800 million and $1.65 billion, once the patents on new drugs expire starting in 2023.

Last year, Industry Canada and Health Canada examined the effect of extending patent protection to European drugs, and found it could increase Canadian drug costs by between $795 million and $1.95 billion annually.

An exchange on the issue between Fast and Davies sparked some partisan fireworks between the two during an early morning committee meeting Thursday.

Davies asked Fast if he had "a clear understanding" of the trade deal's effect on drug costs.

"Do you not have an idea of what the range may be? If so, why don't you share those with Canadians?" Davies asked.

"We have been very open" Fast replied, but Davies interrupted him: "I'm giving you the opportunity to be open."

"Mr. Davies," the minister continued, "we are not going to provide you, or the public with information that is speculative in nature. The information we've been provided is speculative."

"We're confident that the impact on the costs of medicines in Canada will be mitigated by steps that we can take."

Compensation for provinces?

Fast couldn't resist throwing in a partisan shot: "I understand that the NDP is anti-trade," he said.

The Conservative chair of the committee brought the exchange to a quick end.

Fast's remarks echoed past comments by Prime Minister Stephen Harper that Ottawa would consider compensation for the provinces if their drug costs end up climbing because of the deal.

Government officials maintain Canadians won't see any evidence of rising costs for at least eight years.