A French government official Sunday rejected again calls by Electricite de France (EDF.FR) Chief Executive Pierre Gadonneix to raise power tariffs by 20% over three years.

Claude Gueant, an advisor to President Nicolas Sarkozy, said in an interview on Europe 1 radio station that the increase in power prices demanded by Gadonneix was "out of proportion," and that the government was considering a "very limited" increase.

"I find it regrettable that the CEO of EDF worries the French people with the prospect of an increase (in power prices) when he knows very well that the governemnt, which sets tariffs, won't be able to follow him," Gueant said.

Gueant is the third high-ranking government official to rebuke Gadonneix this week. Finance Minister Christine Lagarde said Thursday that the announcement made by the head of state-controlled EDF was "incomprehensible."

In an interview to Le Parisien newspaper, Henri Guaino, another advisor to Sarkozy, said it would be a mistake to make the French consumer pay for EDF's mistakes in its international expansion policy.

In recent years, the French energy behemoth has been buying assets abroad, including its U.K. competitor British Energy, and half of the nuclear reactors of Constellation Energy Group Inc. (CEG) in the U.S.

As a result, last year its debt rose by about 50% to EUR24.5 billion.

Gadonnaix's mandate to lead EDF expires in November.

-By Gabriele Parussini, Dow Jones newswires; +33 1 4017 1740; gabriele.parussini@dowjones.com.