WARSAW, Poland -- Poland's Senate has backed legislation that will regulate Holocaust speech, a move that has already strained relations with both Israel and the United States.

The bill proposed by Poland's ruling conservative Law and Justice party and voted for early Thursday could see individuals facing up to three years in prison for intentionally attempting to falsely attribute the crimes of Nazi Germany to the Polish nation as a whole.

It was approved by the lower house last week. The bill has yet to become law as it requires the approval from President Andrzej Duda, who has supported it.

Although the bill exempts artistic and research work, it has raised concerns that the Polish state will decide itself what it considers to be historic facts. The bill has already sparked a diplomatic dispute with Israel and drawn calls from the United States for a reconsideration.

Though Deputy Justice Minister Patryk Jaki suggested Israel had been consulted on the bill and voiced no objections, many in Israel have argued that the move is an attempt to whitewash the role some Poles played in the killing of Jews during World War II.

Israel's Foreign Ministry said Israel "opposes categorically" the vote by Poland's senators.

"Israel views with utmost gravity any attempt to challenge historical truth," the ministry said in a statement. "No law will change the facts."

Halina Birenbaum, a Holocaust survivor and acclaimed Israeli author, called the new law "madness," telling Israel's Army Radio it was "ludicrous and disproportionate to what actually happened to Jews there."

Expressing surprise at the storm the legislation has unleashed, the Polish government said it planned to issue an explanatory statement later Thursday.

Poland's Deputy Prime Minister Jaroslaw Gowin said the government had acted in "good faith" and the country's foreign ministry said the legislation is intended to "protect historic truth" and "fight all forms of denying and distorting the truth about the Holocaust as well as belittling the responsibility of its actual perpetrators."

Poland's government argues that it is fighting against the use of phrases like "Polish death camps" to refer to camps operated by Nazi Germany in occupied Poland during World War II. Poland was among the hardest-hit victims of Nazi Germany, losing some six million citizens, half of them Jews, and is preserving Holocaust memorials.

The government has expressed hope that adoption of the law will not affect Poland's strategic partnership with the U.S.

Working groups in Poland and Israel are to start discussing the issue this week, although it was not clear what effect it could have on the bill.

Before the Senate's vote, the U.S. asked Poland to rethink the proposed legislation saying it could "undermine free speech and academic discourse" and affect ties with the U.S. and Israel.

Israel's Holocaust memorial, Yad Vashem, issued a statement saying it was "most unfortunate" that Poland was proceeding with a law "liable to blur historical truths" that "jeopardized the free and open discussion of the part of the Polish people in the persecution of the Jews at the time."

Israeli Intelligence Minister who also looks after transport matters, Yisrael Katz said the law constituted "a denial of Poland's part in the Holocaust of the Jews." He called on Prime Minister Benjamin Netanyahu to immediately recall Israel's ambassador from Warsaw for consultation.

"In the balance between diplomatic considerations and moral considerations, there must be a clear decision: perpetuating the memory of the victims of the Holocaust above any other consideration."

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Ilan Ben Zion in Jerusalem contributed to this report.