Venezuela's President Nicolas Maduro talks to supporters during a meeting outside Miraflores Palace in Caracas, December 15, 2015. REUTERS/Carlos Garcia Rawlins

CARACAS (Reuters) - Venezuelan President Nicolas Maduro on Thursday said his government will summon France’s ambassador to protest a letter by that country’s prime minister congratulating the opposition for winning a congressional majority this month.

French Prime Minister Manuel Valls’ letter called the results a “large and uncontestable victory” and expressed hope for the release of “unfairly convicted prisoners of conscience” such as jailed opposition activist Leopoldo Lopez.

“I have told the foreign minister to issue a strong note of protest and to summon the ambassador of France in Venezuela to very clearly explain the conditions for maintaining relations with a free and independent country,” Maduro said in a televised broadcast. “I reject and repudiate the insolent, interventionist and immoral statements by France’s prime minister.”

Valls addressed the Dec. 14 letter to Jesus Torrealba, head of the opposition’s Democratic Unity coalition. On Thursday, he posted a copy of the letter on his Twitter account.

“I wanted to warmly congratulate you and all democratic Venezuelans,” reads Valls letter. “The victory of your coalition opens new perspectives for democracy in Venezuela.”

Venezuela’s opposition will hold a majority in congress for the first time since late socialist leader Hugo Chavez rose to power in 1999.

This month it took two-thirds of the legislature’s 167 seats in a landslide victory driven by anger over the country’s prolonged economic crisis.

The opposition has said the first priority for the new congress will be an amnesty law to seek the release of jailed opposition leaders it describes as political prisoners. Many of those, including Lopez, were jailed for their involvement in several months of anti-government protests in 2014.

Maduro describes Lopez as a dangerous criminal who sought to destabilise his government and has vowed to veto the law.