GAZA CITY, Gaza Strip – Mahmoud Abbas, the leading candidate in next week’s presidential election, yesterday promised Palestinian Arab refugees they’ll be able to return home one day – his most explicit comment yet on an explosive issue that has derailed peace talks in the past.

He’s still far too moderate for the terrorist group Hamas, however, which demanded that he apologize for requesting a halt to rocket attacks against Israel.

Also yesterday, for the first time a soldier called on his comrades to disobey an order to evacuate an unauthorized West Bank settlement, spelling more trouble for the plan to leave the Gaza Strip this summer. The off-duty soldier was arrested, the military said.

With Israeli tanks poised to sweep into northern Gaza on Sunday to put a stop to a wave of mortar and rocket attacks on Israel, Mr. Abbas called for an end to the barrage because it was giving Israel an excuse to invade.

In response, Hamas and several other terror groups released a joint statement demanding that Mr. Abbas apologize.

The groups called the statement “a stab in the back to the resistance … because the resistance has proved that this is the only way to respond to the crimes of the occupation.”

Rhetoric escalated yesterday over the possibility that pro-settlement Israeli soldiers might refuse to carry out orders to evacuate settlements under Prime Minister Sharon’s plan to leave Gaza and part of the West Bank.

Settler leader Pinchas Wallerstein told Army Radio: “If there will be dozens, or hundreds, or thousands of insubordinates, it will take the state of Israel decades to rehabilitate its society.”

Mr. Sharon said soldiers who refuse to carry out orders would be harshly punished. “The law will be upheld,” he said.

Mr. Abbas was campaigning for a third straight day in Gaza, trying to counter his image as a gray bureaucrat who might not stand up to Israel by appealing to young terrorists.

After embracing terror leaders in refugee camps and pledging to stand by the gunmen in their struggle to avoid capture by Israel, Mr. Abbas took an uncompromising stance on the refugee issue. Addressing a rally in Gaza City, Mr. Abbas said Palestinian Arab refugees and their descendants from the two-year war that followed Israel’s creation in 1948 have the right to return to their original homes.

“We will never forget the rights of the refugees, and we will never forget their suffering. They will eventually gain their rights, and the day will come when the refugees return home,” Mr. Abbas told the cheering crowd.

Mr. Abbas himself is from Safed, an ancient city in northern Israel.

The refugees and their descendants total about 4 million people. Almost unanimously, Israeli Jews reject the claim, warning that resettling so many Arabs would undermine the Jewish quality of their state, where about 5 million Jews and 1 million Arabs now live. Some say it is a dark plot to destroy the Jewish state.

Israel’s government believes Palestinian Arab refugees should be settled in the Palestinian state that would be created through peace talks or in the places where they have lived for the last six decades.

Israel offers compensation for lost property, and a previous, more moderate government agreed to take in a limited number of refugees to reunify families.