(CNN) -- A new French law making it a crime to publicly deny the Ottoman Empire's genocide of Armenians a century ago was ruled unconstitutional Tuesday by France's Constitutional Council.
The measure, which triggered condemnation from modern Turkey, was given final passage by the French Senate and signed into law by President Nicolas Sarkozy last month.
Sarkozy's office immediately issued a statement calling for a new version of the law "taking into account the decision of the Constitutional Council."
"The president believes that genocide denial is intolerable and must be punished in this regard," the statement said.
The country's highest judicial body reviewed it at the request of National Assembly members and French senators.
"The Council deems the law unconstitutional," a short statement from the court said Tuesday.
The Turkish government called it "an example of irresponsibility" and vowed to "express our reaction against it in every platform" when the bill passed the National Assembly -- the lower house of the French parliament -- in December.
The Turkish Foreign Ministry issued a statement Tuesday that called it "pleasing that a grave mistake has been corrected by the highest legal authority in France."
"We hope France will from now on be in a constructive attitude for the dispute between Turkey and Armenia on history to be considered on a fair and scientific basis, and will make contributions that support a solution rather than further deepening the problem," the Turkish ministry said. "Such an attitude will contribute to the Turkish-French relations to improve in all areas as well."
Armenia's government hailed the passage last month, saying France "reaffirmed its pivotal role as a genuine defender of universal human values."
It is already illegal in France to deny the Holocaust of World War II, a crime punishable by a year in prison and a fine of 45,000 euros (about $60,000). The same punishment would apply under the Armenian legislation.
The Turkish-Armenian controversy over the killings that took place last century has reverberated wherever diaspora communities representing both groups exist. Armenian groups and many scholars argue that Turks committed genocide starting in 1915, when more than a million ethnic Armenians were massacred in the waning days of the Ottoman Empire.
Turkey officially denies that a genocide took place, saying hundreds of thousands of Armenian Christians and Turkish Muslims died in intercommunal violence around the bloody battlefields of World War I.
Sen. Herve Marseille, one of the bill's supporters, argued that since France already recognizes the Ottoman-era killings as genocide, the same standard that applies to Holocaust denial should apply to the Armenian case.
"When we contest the Jewish genocide, we can be punished," Marseille said. "And up until now, when we contest the Armenian genocide, there is no punishment. So we can't have a legal punishment for one and not for the other. Everyone is equal in front of the law."
But Sen. Jacques Mezard, who opposed the legislation, said freedom of expression was at stake.
"It calls into question historical and scientific research. Tomorrow will there be a question of a Vendee genocide?" he asked, referring to a revolt against the French revolutionary government in 1793. "Will we put the Spanish and the United States in the stocks for the massacre of Native Americans? We must reject this text and consign it to history books."
After December's vote in the National Assembly, Turkish Prime Minister Recep Tayyip Erdogan accused France of committing its own "genocide" during its war against Algerian independence in the 1950s and 1960s. Erdogan announced that Turkey was reviewing its ties with France. Ankara recalled its ambassador to Paris for consultations, canceled bilateral visits and wouldn't cooperate with France in joint projects within the European Union.
The French Foreign Ministry shot back at Erdogan's comments, saying France "assumes with clarity and transparency its duty to remember the tragedies that have marked its history." And Sarkozy has said that his country doesn't need an OK from another nation to develop its policies.
In addition to being NATO allies, Turkey and France have trade ties valued at $13.5 billion, according to Turkish statistics.
The genocide debate is also a source of tension between Turkey and the United States, another NATO ally. The White House, for example, annually beats back efforts in Congress to pass a resolution that would formally recognize the 1915 massacre of Armenians as genocide.
CNN's Saskya Vandoorne contributed to this report.