Germany's Vice Chancellor Sigmar Gabriel won a crucial mandate within his Social Democratic party (SPD) on Europe's free trade agreement with Canada on Monday.

The Vice Chancellor and SPD leader, who is also the country's economy minister, had tied his fate to the success of his party's support for the 'Comprehensive Economic Trade Agreement' (CETA), a free trade deal between the European Union and Canada. His failure to secure a majority of delegates at Monday's SPD convention in Wolfsburg now calls into question whether Gabriel will lead the SPD into next year's national elections.

SPD divided over CETA

Ahead of the vote, CETA had proven divisive within the SPD. The left and youth wing of the party had come out as the strongest critics to the trade deal. Chair of the SPD's left wing, Hilde Mattheis, directed her concern at the agreement's investment provisions clause. Critics say that it places the legal rights of private companies and investors over those of individuals. "I do not want CETA to protect investors rather than citizens," she said.

Head of the youth wing Johanna Uekermann told the broadcaster NDR that the current agreement risks softening Germany's basic public provisions, such as infrastructure and schooling.

Gabriel with Canadian Prime Minister Justin Trudeau

Powerful figures within the party did come out in support of Gabriel and his mandate for the EU to complete negotiations with Canada under the current framework. Among them were European Parliament president Martin Schulz, Foreign Minister Frank-Walter Steinmeier, and the SPD General Secretary, Katarina Barley.

Supporters of the deal in Germany stress that a trade agreement is crucial to preserving the country's role as an export nation.

Gabriel maintained that ratifying the agreement was Europe's best chance to shape globalization so that it serves people's interests, and not just those of companies.

The SPD leader returned from Canada shortly before the vote. He told the German parliament that he and his Canadian counterparts had agreed on key concessions in the deal, particularly regarding environmental matters.

It seems that the concessions were not enough to form a compromise within his party.

The contents of CETA

The CETA agreement is designed to eliminate tariffs on 98 percent of traded goods between the European Union and Canada. The deal would also incorporate common policies on regulatory cooperation, shipping and sustainable development.

Critics stress that CETA would undermine worker's rights and environmental standards in Europe. Another common criticism is that it serves as a blueprint for the controversial Transatlantic Trade and Investment Partnership (TTIP) deal between the EU and the United States.

Demonstrators in Berlin protest the CETA and TTIP deals.

Ahead of the vote, around 180,000 demonstrators took to the streets in major German cities to protest against the CETA and TTIP deals.

The deal is scheduled to be signed by Ottawa and Brussels next month. However, each EU member state would then need to fully ratify the agreement for it to come into force.

dm/jil (Reuters, AFP, dpa)