OTTAWA -- Canada is working with the European Union to revise controversial investor protection provisions in their landmark free trade deal at the direction of the new Liberal government.

But Canada's chief negotiator Steve Verhuel said Tuesday the ongoing work with the EU does not mean the pact has been reopened to negotiation.

The comprehensive deal in goods and services, known as CETA, has been plagued with delays since negotiations were publicly declared finished in the summer of 2014 after what was then five years of talks.

"We're not re-opening the negotiations at all," Verhuel told the House of Commons trade committee.

The government wants to see if improvements can make the dispute-resolution mechanism more favourable to Canada, he said.

The Europeans first raised the matter after political opposition arose in Europe in 2014 over the chapter that deals with settling disputes between companies and governments, known as ISDS.

Some European politicians and anti-trade activists have raised concern that the investor-state dispute settlement chapter would give big companies the power to sue governments for creating regulations that affect their profits.

They say it could undermine the ability of countries to regulate environmental and health policies, among other things.

European officials, including most recently the EU ambassador to Canada, have said they don't see ISDS as an impediment to the deal being implemented.

Verhuel was responding to a question from the NDP trade critic Tracey Ramsey, who asked whether the new Liberal government wants him to "to take CETA in a new direction" on ISDS or any other part of the deal.

"I wouldn't call them instructions at this point. We've certainly had a dialogue about potential improvements that could be made," Verhuel said.

"We have had an interest on our side in seeing whether we can make some improvements in light of that and that's been supported by the government."

Part of ongoing discussion with the EU includes, "clarifying some of the provisions in the agreement with respect to the obligations to ensure that the government's right to regulate is not interfered with by investor claims that could affect that ability to regulate."

Verhuel said he expects the deal to be ratified and fully implemented next year.

That's essentially the same timeline that the EU ambassador to Canada, Marie-Anne Coninsx, offered in a recent interview.

Like Coninsx, Verhuel said the deal is now in the legal "scrubbing" phase and is in the process of being translated into French and more than 20 official European languages.

But Ramsey said in an interview that it is unclear from what Verhuel told the committee whether the deal is actively being negotiated rather than simply translated and legally vetted.

"We have the chief negotiator saying they are working on rewriting sections of the deal," said Ramsey.

She said the Liberals have not brought any more clarity to the trade talks than the previous Conservative government, which negotiated the deal.

"All of this is happening in secret," said Ramsey. "I'd like the Liberals to level with Canadians -- let us know what's on the table and also what they're up to."