Left-leaning politicians in Belgium remain on the verge of scuppering the controversial Comprehensive Economic and Trade Agreement (CETA) trade agreement between the EU and Canada.

Belgium cannot support the deal without the backing of all of its regions and the French-speaking Wallonia has not been convinced to support the deal during last gasp talks.

AFP now reports that today's summit has been cancelled without a new date being set.

Yesterday, Taoiseach Enda Kenny reiterated Ireland's support for the deal, he told the Dail that CETA would not impact on labour rights, or environmental protection.

CETA's main point of contention is the investor-state dispute settlement (ISDS) mechanisms included in these agreements. This allows businesses to take legal actions against governments who introduce new laws which threaten future anticipated profits.

These cases are heard by a three person international tribunal. While courts like this have been criticised for a lack of transparency, the EU says that it has taken a number of measures to address these concerns and to make the legal process as fair and open as possible.

Famously, the ISDS provision in a free trade agreement between Australia and Hong Kong allowed the tobacco company Philip Morris to attempt to sue the Australian government after it introduced plain packaging laws.

Paul Magnette, Wallonia's socialist leader, highlighted this issue as the sticking point in negotiations, saying: "Difficulties remain, especially on a symbolic and extremely important politically issue: the settlement mechanism."

"The mechanism is not described with precision ... It's like buying a cat in a bag," he told the the Walloon parliament.