The pressure on Mahmoud Abbas to back down from plans to seek recognition of Palestinian statehood at the United Nations in September is intensifying.

Squeezed by a combination of concerted American pressure and intense Israeli diplomacy, some top Palestinian leaders are urging the Palestinian Authority’s president to drop his September plan.

Abbas, however, says he still intends to go ahead with the U.N. move, unless key international players can get serious peace talks going before then.

“If the Americans, the Europeans and Israel don’t want us to go to the U.N., they must show me an alternative,” he said in an interview on Lebanese TV on Monday.

The P.A. president repeatedly has declared that he prefers negotiations with Israel to the U.N. gambit, but he insists on a negotiating framework with clear terms of reference. So far, the United States and others have been unable to produce a formula acceptable to both sides. At least for now, Abbas is saying he won’t abandon his U.N. strategy in the absense of such a framework.

But the pressure is growing.

By far the strongest source has been President Obama’s firm opposition to any Palestinian U.N. move. Obama’s promise to veto any bid in the Security Council for Palestinian U.N. membership means that the best the Palestinians can hope for is symbolic recognition by the U.N. General Assembly, not full membership in the world body. And Obama has been exerting heavy pressure on the Europeans to oppose the Palestinians’ recognition push.

Obama’s position has been reinforced by several congressional initiatives. In December, Congress passed a resolution “condemning unilateral measures to declare or recognize a Palestinian state.”

Last week, Rep. Steve Chabot, the Republican chairman of the House Foreign Affairs Committee’s Middle East subcommittee, urged the administration to withhold U.S. contributions to the United Nations if it recognizes a Palestinian state. There is also a looming Congressional threat to cut off $513 million in U.S. funding for the Palestinian Authority if it goes ahead with plans to bring Hamas, a designated terrorist group, into the Palestinian government.

The specter of U.S. economic pressure backed by widespread Western diplomatic opposition has been having a sobering effect on the Palestinians.

A pro-Western wing of the Palestinian leadership, led by P.A. Prime Minister Salam Fayyad and including former Palestinian envoy to the U.N. Nasser al-Kidwa, is advising Abbas to drop the U.N. initiative mainly for the sake of good relations with the United States.

They also fear that a U.N. resolution which fails to change anything on the ground could spark a new cycle of violence and retaliation, destroying years of state-building achievements, especially in the Palestinian economy and security forces.

To soften U.S. opposition, Palestinian supporters of the U.N. gambit, like Abbas and his chief negotiators Saeb Erakat and Nabil Shaath, are proposing sending an accompanying letter to the U.N. recognizing Israel in the 1967 borders and committing to resume negotiations immediately on a state-to-state basis. That, however, is unlikely to cut much ice.

Meanwhile, the Israeli Foreign Ministry has launched a worldwide campaign against U.N. recognition of a Palestinian state, instructing Israeli embassies across the globe to leave no stone unturned. Even in countries considered lost causes, diplomats have been ordered to do all they can to turn things around.

The aim of the intense Israeli diplomatic activity is twofold: First, to prevent the Palestinians from winning a two-thirds majority in the 192-member General Assembly. Then, if that fails, at least to win what Israeli officials are calling a “moral minority” – in which most Western countries, with their moral authority as democracies, vote against recognition of a Palestinian state.

“There is no possible configuration in which Israel wins the vote,” a senior aide to Israeli Prime Minister Benjamin Netanyahu told JTA. “But if we can get that ‘moral minority,’ then the resolution will be reduced to nothing more than another U.N. anti-Israel piece of paper.”

As part of the campaign to win over the European democracies, Netanyahu has been warning European leaders that a U.N. resolution which enshrines the 1967 borders will kill off the peace process.

He argues that no Palestinian leader will be able to accept anything less, undermining the long-accepted principle that in any peace treaty the 1967 lines will have to be modified.

“It will have the same effect as the 1948 U.N. General Assembly Resolution 194 had on the refugee issue,” the Netanyahu aide insisted, referring to the resolution that stipulated that Palestinian refugees wishing to return to home should be permitted to do so, and that compensation should be paid to those who do not.

“Everyone understands that in a peace treaty Palestinian refugees will return to Palestine, not to Israel,” the aide said. “But because of 194, you have a situation in which no Palestinian leader is ready to say so in public.”

Israeli Foreign Minister Avigdor Lieberman goes further. In a mid-June meeting in Jerusalem with the European Union’s foreign policy chief, Catherine Ashton, he warned that if the Palestinians made a unilateral approach to the United Nations, they would be in violation of the Oslo agreements, and Israel would no longer consider itself bound by them. Lieberman was picking up on the opinions of several leading Israeli legal experts, including former foreign ministry legal adviser Alan Baker.

Baker, who was closely involved with the Oslo negotiations, claims that by trying to get the international community to unilaterally impose Palestinian positions on Israel, the Palestinians are in breach of the 1995 Oslo interim agreement, which set up the Palestinian Authority and its presidency and parliament on the understanding that all remaining differences would be resolved through negotiations.

“The Palestinian approach to the U.N. violates the interim agreement and, in so doing, undermines the legal basis of the P.A. and all the other Palestinian institutions, creating the potential for legal chaos,” Baker told JTA.

Israel’s legal and diplomatic arguments have apparently struck a chord in some European capitals. Germany, Italy and the European Parliament have all made their opposition to a unilateral Palestinian U.N. move clear.

Clearly, Abbas is trying to use the specter of September as a stick to get a resumption of peace talks on his terms. But as long as Hamas is part of the Palestinian government, the chances of talks being renewed are slim.

And unless Abbas is persuaded to back down at the 11th hour, the diplomatic battle is more likely to shape up over what comes next: Does U.N. recognition of Palestine isolate Israel, or does it backfire and leave the Palestinians worse off than before?