It is likely to secure backing in the Canadian and European parliaments, but support from the 28 members is far from certain.
"If the two closest allies in the world cannot agree a deal, then who can?" EU Trade Commissioner Cecelia Malmstrom told the European Business Summit in Brussels. Her view was echoed more bluntly by Canadian Trade Minister Chrystia Freeland.
"If the EU cannot do a deal with Canada, I think it is legitimate to say who the heck can it do a deal with," she said.
Malmstrom said her hope was that the deal would be adopted before the end of October when it could be signed during a planned visit to Brussels by Canadian Prime Minister Justin Trudeau.
The Commission needs to determine in the next month whether it can be cleared by governments alone or if each country needs to push the trade deal through their parliaments - or in Belgium's case four parliaments, one of which opposes the agreement.
Bulgaria and Romania have also expressed reluctance given Canada does not extend its visa-waiver entry system to their citizens.
The deal is also facing opposition from campaign groups and trade unions, who say CETA is as dangerous as their bete noire - a planned EU-U.S. trade deal called the Transatlantic Trade and Investment Partnership (TTIP). They say the deals hand power to multinationals and are a threat to democracy.
Groups in Austria and Germany, which proponents say would benefit most from a trade deal, have staged a series of anti-TTIP and CETA rallies, with a large demonstration planned in Berlin on Sunday.
The Dutch also voted against a trade deal with Ukraine in a referendum in April.
"We must be mindful that all 28 countries and the European Parliament are very demanding institutions ... We can't have local referendums on all trade agreements," Malmstrom said.
The commissioner also expressed frustration that politicians voiced strong support for trade deals at EU meetings then briefed local media about their doubts.
A frustrated Commission President Jean-Claude Juncker will urge EU leaders at a summit this month to back free trade talks with the United States in the face of growing scepticism in member states.□
Philip Blenkinsop , Reuters