Israel will not negotiate with any new government hand-picked by Yasser Arafat (search), the Israeli foreign minister said Sunday in the first public warning to those trying to topple beleaguered Palestinian Prime Minister Mahmoud Abbas (search).

A power struggle between Arafat and Abbas has intensified in recent days, with clashes over key appointments and control of security forces.

Several Palestinian legislators, including Arafat allies, are lobbying to oust Abbas later this week after he presents the achievements of his first 100 days in office to parliament. It remains unclear whether the session will be followed by a vote of confidence.

Israeli Foreign Minister Silvan Shalom (search) suggested Sunday that an already troubled U.S.-backed peace plan, the so-called "road map," would be derailed if Abbas is ousted.

"Israel will not negotiate with a new government formed under the instructions and the influence of Arafat," Shalom said after a meeting with EU foreign policy chief Javier Solana in Tel Aviv (search).

Arafat reluctantly appointed Abbas as the Palestinians' first prime minister in April under pressure from Israel and the United States, which have accused Arafat of blocking peace efforts.

Parliament Speaker Ahmed Qureia, considered a possible Abbas replacement, said Sunday that the infighting is harming Palestinian interests. Outside support for Abbas, including from Israel and the United States, "is complicating the crisis," he cautioned.

Abbas has minimal support among Palestinians, many of whom say they distrust him because he has Israel's backing. And while Arafat also has lost popularity after failing to deliver on promises of statehood, the 74-year-old remains a symbol of hoped-for independence.

A Palestinian parliament meeting scheduled for Monday was pushed back to Thursday, to allow Abbas to garner support.

Lawmaker Qadoura Fares, a member of Arafat's Fatah movement, said he and others plan to present a possible compromise that would increase Arafat's influence but keep Abbas in power. "Arafat should support the decisions of the government and should be consulted on the basic issues," Fares said. Arafat also would head a new five-member national security council.

The United States and Israel have warned that ousting Abbas would hurt peace efforts. Both have urged Arafat to give Abbas full control of security forces for a crackdown on militants, but Arafat has resisted.

Israeli Defense Minister Shaul Mofaz said it appeared a "double-headed government has been created," with Arafat and his security adviser, Brig. Gen. Jibril Rajoub, maneuvering against Abbas and security chief Mohammed Dahlan.

"I believe that the relationship between these two heads has reached the point of a serious conflict, to the point of collision," Mofaz said, accusing Arafat of "using every tool available in order to cause the process to fail."

Meanwhile, Palestinian gunmen seriously wounded an Israeli construction worker building an Israeli security barrier near the West Bank town of Qalquiliya on Sunday, the army said. In response, troops and tanks entered the city to search for gunmen and imposed a curfew.

In another shooting, Hamas gunmen wounded an Israeli motorist near a Jewish settlement in the Gaza Strip. The man was in critical condition.

In Italy, Pope John Paul II decried violence in the Middle East and prayed for reconciliation.

Solana urged progress on the "road map" peace plan, saying it is "the only document on the table." He also said European leaders would discuss taking financial steps against Hamas as requested by Israel and the United States.

The EU foreign policy chief hopes to find a compromise with Israeli officials over their objections to European envoys meeting with Arafat. However, Shalom on Sunday declared Arafat "an obstacle to peace," suggesting Israel is not willing to soften its stance.

For nearly two years, Israeli troops and threats have kept Arafat stranded at his sandbagged West Bank headquarters, which has been heavily damaged by tank shells and bulldozers.

Options for further isolating Arafat include cutting the phone lines to his compound, a senior Israeli official said on condition of anonymity.

Meanwhile, Mofaz said Israel has the option of sending troops into the Gaza Strip. Troops and tanks have been massed along the border in recent days, and Mofaz said Israel could send them in "when we decide it would be correct to do so."

Israel intensified its targeted killings of terror suspects after an Aug. 19 homicide bombing that killed 21 people. Since then, Israel has killed 10 Hamas members and three bystanders in missile strikes.

Palestinians have fired mortars and homemade rockets at Israeli settlements in Gaza and population centers in Israel, including the coastal city of Ashkelon.

Visiting a school in Ashkelon on Sunday, Israeli Prime Minister Ariel Sharon said the town "will not become another front" in the conflict.

"There is one area that Israel can't make concessions on -- this is the area of security," the prime minister said.