The talks have dragged on for four years now, with both sides blaming the other for the delay.
But now a number of influential business leaders have a simple message for the two leaders: stop talking and start trading.
"It's left the negotiators' table. It's now on the decision-makers' table, and one of two things happens at this stage," John Manley, president of the Canadian Council of Chief Executives, said in an interview Thursday.
"Either the necessary accommodations are made to finalize a deal, or it just goes sideways and everybody forgets about it."
Manley is one of 10 business representatives from Canada and Europe who signed a letter sent Thursday to Harper and Barroso.
They say they want a deal that includes full access to government procurement markets, at both the national and provincial or regional levels. The agreement should also cover intellectual property, they say, particularly in the life sciences industry. And they want it to open agricultural and industrial markets.
"Great progress has been made, narrowing the outstanding questions to a handful of politically sensitive issues," the letter says.
"While we recognize that for these outstanding issues choices at the highest levels are required to ensure a balanced deal, we encourage both negotiating parties to strive for comprehensive and ambitious solutions that benefit economies on both sides of the Atlantic.
"The EU and Canada must stay focused on the bigger picture and the overall gains of $30 billion annually in the bilateral commercial relationship with a successful conclusion to the CETA."
Beef and pork had been among the biggest sticking points, but the two sides recently reached a tentative settlement. It's unclear precisely which issues still stand in the way of a deal.
Earlier this year, an EU trade spokesman took the unusual step of blaming Canada for holding up the negotiations. Harper and his Conservative government shot back, saying they would not sign any deal that wasn't in Canada's best interests.
There has also been some concern that Canadian and European negotiators could put their talks on the back burner when the EU starts separate free trade talks with the United States.
With a federal election two years away, Harper's Conservative government faces political pressure to sign a deal with the Europeans to help burnish its economic credentials.
Politics aside, Manley says the importance of getting a Canada-EU free trade deal can't be underscored enough.
"You know, governments have exhausted their abilities to grow their economies either through fiscal stimulus or monetary policy," he said.
"The only thing left is really to grow trade."