President Nicolas Sarkozy warned Thursday that abandoning nuclear power would cause "considerable damage" to France after his opponents vowed to campaign to reduce the country's reliance on atomic energy.

"Wanting to abandon this energy, or to arbitrarily reduce its share in our energy mix without providing solutions for its substitution... would mean considerable damage to French industry," Sarkozy told a meeting of business leaders.

France's opposition Socialists and Greens this week agreed a deal to jointly campaign for France to reduce its reliance on nuclear energy from more than 75 percent to 50 percent by shutting 24 nuclear reactors by 2025.

The Greens say that alternative energy sources like wind and solar power would compensate for the effects on the economy of abandoning atomic power.

France is the world's most nuclear-dependent country, operates 58 reactors and has been a leading international proponent of atomic energy.

"I will not sell off this advantage of France, it would be irresponsible and would have consequences for our industries," Sarkozy said.

"I will not call into question what has been an exceptional asset for France," he said, adding that the country's longstanding support for nuclear energy had been the result of a rare "political consensus".

"This is not about politics, this is not about the left or the right, this is not about the opposition or the majority, this is about France," Sarkozy said.

The opposition deal marked the first significant move toward limiting nuclear power in France since it embraced atomic energy after the oil shocks of the 1970s and came amid growing disquiet after Japan's Fukushima atomic disaster in March.

Under the deal the Socialists will not stand in a number of constituencies in order to boost the Greens' electoral hopes and give them at least 15 seats in a new parliament.

In exchange the Greens will support Socialist candidates in the second rounds of the presidential and parliamentary votes.

France will vote in the first round of a presidential election in April and potentially a second round in May, followed by a two-round parliamentary election in June.