WASHINGTON —  Half the Democratic caucus in the U.S. Senate urged President Barack Obama to suspend assistance to the Palestinian Authority unless Hamas recognizes Israel and renounces terrorism.

“It is imperative for you to make clear to President [Mahmoud] Abbas that Palestinian Authority participation in a unity government with an unreformed Hamas will jeopardize its relationship with the United States, including its receipt of U.S. aid,” said the letter sent May 6 to Obama and signed by 27 Democratic senators.

Abbas’ Palestinian Authority signed a reconciliation deal with Hamas this month.

The letter from the Democrats notes that U.S. law proscribes assistance to any government that includes Hamas, unless it and its ministers comply with principles laid down by the Quartet, the grouping that includes the United States, the Russia, the European Union and the United Nations. Those principles include recognizing Israel and renouncing terrorism.

Under that formulation, the Obama administration could have relations with a PA government that has the support of Hamas but does not include its members at cabinet-level positions. Administration officials have not counted out such a scenario.

However, the letter, initiated by New Jersey Sen. Robert Menendez, suggests that Obama go further than the letter of the law and condition relations not on the government’s makeup but on Hamas’ posture.

“We urge you to conduct a review of the current situation and suspend aid should Hamas refuse to comply with Quartet conditions,” it said in language that was backed by the American Israel Public Affairs Committee in a recent backgrounder.

Separately, Florida Democrat Rep. Alcee Hastings last week introduced a non-binding resolution in the U.S. House of Representatives that also urged cutting off assistance to a Palestinian Authority that includes Hamas.