BRUSSELS (AP) — The European Union and Canada are preparing to sign a landmark trade pact, ending days of drama after a small Belgian region refused to endorse the agreement and deeply embarrassed the EU.

The long-delayed Comprehensive and Economic Trade Agreement was bedeviled by yet another hold up early Sunday when Canadian Prime Minister Justin Trudeau's plane had to return to Ottawa due to mechanical issues.

The scheduled two-hour EU-Canada summit is now due to start in Brussels at 1100 GMT.

Trudeau will sign the pact with European Council President Donald Tusk, EU Commission President Jean-Claude Juncker, and Slovak Prime Minister Robert Fico, whose country holds the EU's rotating presidency.

Politicians in Belgium's Wallonia region argued the deal would undermine labor, environment and consumer standards and allow multinationals to crush local companies.