Cañete ran into a barrage of criticism over past links with the oil industry and last-minute changes in his statement of financial interests.
The formation of a new European Union executive has run into trouble.
Two days ago the hearing of Spanish commissioner-designate for climate and energy Miguel Arias Cañete revealed mounting opposition among MEPs against his appointment in the Juncker commission.
And now an Avaaz campaign has mobilised over 438,000 people across Europe to call on the Commission's new President, Jen-Claude Juncker, to put chuck on the political scrap-heap.
After the approval of the first ten of the nominees in the first two days of hearings, angry scenes in parliamentary committee rooms yesterday threatened to disrupt a timetable under which the new Commission is supposed to be approved en bloc on 22 October and to take office on 1 November.
The most controversial candidate so far appears to be Cañete, a former agriculture minister, who ran into a barrage of criticism over past links with the oil industry and last-minute changes in his statement of financial interests.
Besieged with questions, Cañete said he had resigned as patron of the Faes Foundation, that he no longer receives salary as president of the Popular Party National Electoral Committee and that he had sold his shares in the oil companies Ducar and Petrologis.
Dodging MEPs' questions
Cañete repeatedly dodged questions about his brother-in-law's interest in energy firms. Although the commissioner-designate insisted that both he and his wife and son are now completely detached from this sector, several MEPs asked repeatedly about his brother's relationship with corporate shareholders of the two companies in question.
After several evasive answers, Cañete stated that the declaration of interests submitted to the European Parliament refers only to his closest family, and insisted that he had gone beyond the requirements of the Commission's code of conduct.
But he repeatedly dodged questions about his brother-in-law's interest in energy firms.
Cañete also apologised for having made what he called an inappropriate sexist comment during this year's European Parliament election campaign.
After a debate against a female candidate, he had said debating a woman was hard because a man who used his "intellectual superiority" might appear chauvinist.
Marriage between Climate and Energy
In the hectic debate, Cañete sometimes was able to address issues related to his designated portfolio. He defended the union of Climate Action and Energy, since, in his view, those are "two sides of the same coin".
The commissioner-designate says his intention was to promote renewable energy and work for greater energy efficiency, so that the EU could be "a leader" in the fight against climate change.
As he has said, Cañete has always supported the proposals of outgoing Connie Hedegaard Climate Action Commissioner, and the objectives of the EU executive, which demand the reduction of greenhouse gases.
However, the Greens and the leftist European United Left / Nordic Green Left accused him of not having promoted this policy during his time as Minister of Environment in Spain. Cañete was under severe attack for his domestic policies on shale gas, and also on the import of oil from Canada, a country exploiting tar sands.
Cañete still advocated the creation of a single energy market. He spoke in favour of greater energy independence of the EU from Russia and insisted the South Stream pipeline project should be frozen until all legal problems relating to it are solved.
If South Stream is built in contravention of EU law, it will be an instrument of a foreign power on EU soil, he said.
Green and GUE / NGL groups promoted the manifesto #StopCañete, which so far have signed up more than 80 MEPs, also from the group Europe of Freedom and Direct Democracy, and some MEPs from the Socialist group.
Avaaz petition: A "Petrolhead" as the next Climate Commissioner?