More than a dozen House Democrats have signed a draft letter urging the Trump administration to recognize a Palestinian state, and the leader of the effort said on Monday that he planned to introduce a resolution to codify the push.

“We believe recognizing Palestinian statehood and obligating Palestinian leaders to abide by the international law binding on states and their governments will make that far more achievable and sustainable than decades of statelessness and repression have,” said the letter, which 13 progressive lawmakers have signed so far.

The letter is expected to gather additional signatures before it is sent to President Trump and Secretary of State Marco Rubio next month. No Republicans have joined the effort or signaled their support, making it unlikely that the letter will influence policy decisions from the president or the State Department.

The effort began last week, when Representative Ro Khanna, Democrat of California, circulated a draft, a standard practice to build consensus before a public announcement. Mr. Khanna said the letter, which was reported earlier by Jewish Insider, was leaked in an attempt to derail the effort, a move he criticized but said would not slow him down.

“You cannot sabotage an idea whose time has come,” he said in a statement on Monday.

The push builds on similar efforts in the last Congress, and lawmakers leading the effort said they expected it would draw additional support from colleagues alarmed by the worsening humanitarian crisis in Gaza who have become more willing to publicly criticize the actions of the Israeli government.

The letter also reflects recent actions by some of Israel’s closest Western allies. The leaders of Britain, Canada and France have announced in recent weeks that they intend to recognize a Palestinian state.