Former French environment minister Delphine Batho on Thursday blamed her sacking -- the first in President Francois Hollande's government -- on powerful pro-nuclear energy and shale gas lobbies.

Batho, whose ministry's expenses for next year were cut by seven percent, was axed on Tuesday for describing the belt-tightening budget as a "bad" one.

French ministers are traditionally not supposed to criticise policy decisions publicly even if they are personally opposed to them.

But the 40-year-old denied any wrongdoing, telling reporters: "I did not lack in showing governmental solidarity."

Batho said she was a victim of pressure from economic interests who wanted to overturn a 2011 fracking ban and were opposed to her aim of cutting France's dependence on nuclear energy by developing renewable energy sources.

"Certain powerful economic interests did not accept my high ambitions for energy transition," she said.

"These forces have not hidden their desire for my head, but if the government had been united, they would not have succeeded," she said.

French business lobbies have stepped up a campaign in favour of shale energy development, which commonly uses fracking. They say it would reverse industrial decline, raise competitiveness through cheaper energy and create jobs.

Batho also attacked Prime Minister Jean-Marc Ayrault for not discussing the budget cuts with her or other ministers and denounced it as a form of enforced austerity "which will pave the way for the far-right to take power in our country."

Her dismissal comes amid efforts by Paris to bring its budget deficit down to European Union norms.

French government spending is set to fall next year for the first time since 1958 owing to a slew of austerity measures.

Ministries are expected to achieve cuts of about 1.5 billion euros ($2 billion) in central government spending in 2014 from this year's level.

France aims to cut the budget deficit to 3.9 percent of gross domestic product in 2013 from 4.8 percent last year, then to 3.6 percent in 2014 and 2.8 percent in 2015.