Deputies will vote in Strasbourg on Wednesday after a morning debate on the landmark deal, which aims to boost goods and services trade and investment flows.
Canadian Prime Minister Justin Trudeau is due to address MEPs on Thursday, the day after the key vote.
CETA is the outcome of seven years of negotiations but remains the subject of controversy.
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Its supporters say it will cut more than €500m in tariffs on EU products entering Canada and exports are predicted to rise by over 20 per cent.
However, there is plenty of opposition to CETA. Over three million people across Europe have signed a petition calling for the deal to be scrapped, arguing that it will hand a raft of new powers over to corporations.
It is the first free trade agreement completed with another major established OECD economy.
Members will also vote on the parallel political EU-Canada strategic partnership agreement.
On Monday, Parliament's EPP group - the assembly's biggest - said it will support the deal, arguing that it will save European exporters more than €500m every year because nearly all import duties between the two countries will be eliminated.
German MEP Manfred Weber, group leader, said, "It guarantees market access and creates a level playing field for businesses, advances EU agricultural interests by protecting 145 European geographical indications and safeguards property rights in an international context, while respecting high environmental, consumer and labour standards."
Support also came from the ECR group shadow rapporteur on CETA, David Campbell Bannerman, who said, "This agreement is not just about figures on a piece of paper. It will mean more trade, more jobs and cheaper prices.
"It sets a new benchmark for opening trade and increase cooperation with major western economies. Those who oppose CETA need to explain to their voters why they want to discourage new jobs, and keep prices artificially high. In the long run, more open trade with the EU is a benefit for us all."
However, the Greens in Parliament said they remain "strongly opposed" to CETA and will call for Parliament not to give its consent. Greens/EFA group MEPs, who will take part in a demonstration outside Parliament on Wednesday, said the deal poses "serious threats to public services, workers' rights and the environment."
A Greens source said, "At the very least, the ratification procedure should be suspended until compatibility with the EU treaties has been tested by the European Court of Justice."
European Green Party leaders Reinhard Bütikofer and Monica Frassoni, along with Greens/EFA goup co-Chairs Ska Keller and Philippe Lamberts, have written to Trudeau ahead of the vote outlining their concerns.
The letter reads, "Obviously, we cannot do the CETA negotiations all over again, so we can but state that the agreement is plagued with considerable faults that could have been avoided if things were done differently from the beginning."
Opposition has also come from the NGO community, with a report by Brussels-based campaigners Corporate Europe Observatory (CEO) warning that CETA will "further empower corporate lobbyists by providing them with early, exclusive access to the legislative process."
Possible problems, says the report, are based on experiences with the US-Canada Regulatory Cooperation Council (RCC), which forms part of the North American NAFTA deal and has in some ways acted as the template for CETA's Regulatory Cooperation Forum.
CEO's trade policy campaigner Lora Verheecke said, "When the Canadian and US administrations jointly assessed six chemicals under NAFTA regulatory cooperation, their working group was dominated by big business lobbies, including some which had been instrumental in delaying a proposed ban on harmful pesticides in the EU.
"Here, as well as in Canada, CETA is linked to high risks for public health and environmental protection."
Nick Dearden, the director of campaign group Global Justice Now said, "This trade deal has very little to do with trade, and everything to do with handing corporations a frightening raft of new powers with which to alter laws and regulations to their benefit.
"Millions of people across Europe have clearly stated that they want this toxic trade deal to be scrapped, and it would be a travesty for democracy on Wednesday if MEPs ignore them."
An expert opinion on CETA and Brexit has shown that if the UK doesn't formally leave the EU before CETA is ratified, then it would be tied into the 'corporate courts system' of the trade deal for a period of 20 years after announcing any intention to leave the deal.