In their final session, lawmakers from Abbas' defeated Fatah Party gave the Palestinian leader the authority to appoint a new constitutional court that would serve as the final arbiter in disputes between him and a Hamas government.
A fuming Hamas termed the 11th-hour legislation "illegitimate" and vowed to overturn it. One of its incoming legislators called the legislation "a bloodless coup."
Abbas, who was elected separately last year for a four-year term, is a moderate who seeks to resume peace talks with Israel. The strengthening of his powers and weakening of Hamas comes as Israel tries to diplomatically isolate Hamas unless it renounces violence and recognizes the Jewish state.
The lawmakers also appointed Fatah loyalists to four key jobs, including the head of the government watchdog group in charge of weeding out official corruption. Hamas won last month's parliament elections largely on a promise to end years of nepotism, graft and mismanagement by Fatah.
Hamas would need a two-thirds majority — or 88 of 132 seats in parliament — to change Monday's legislation and it was unclear whether the group would muster such a majority. It will control 74 seats in the new parliament, but can also count on support from several independents.
Hamas' stunning Jan. 25 victory ousted Abbas' long-ruling Fatah Party and touching off Western threats to cut off hundreds of millions of dollars in badly needed aid unless the group abandons its violent ways and recognizes Israel's right to exist.
With the new, Hamas-dominated legislature scheduled to convene for the first time on Saturday, the old legislature struck hard in its last session.
Parliament empowered Abbas to appoint a new, nine-judge constitutional court that would have the authority to resolve any dispute between him and the incoming Hamas-dominated parliament or Cabinet. The court also could veto legislation deemed to violate the Palestinians' Basic Law, a forerunner to the Palestinian constitution.
Legal expert Issam Abdeen said the new legislation would let Abbas "cancel any law approved by the new parliament on the pretext it is unconstitutional."
"The new amendment gives President Mahmoud Abbas power over the laws of the new Palestinian legislature, since he is the one who appoints the judges of the constitutional court," Abdeen said. "He can use (these powers) to nullify laws that are unacceptable to him. If Hamas now approves Islamic laws, he could say it is against the constitution."
Hamas spokesman Said Siyam said parliament had no right to make last-minute changes and the group would overturn the old parliament's decisions.
"The parliament has no mandate and no authority to issue any new legislation," he said, calling Monday's action "illegitimate."
Abdel Aziz Duaik, an incoming Hamas legislator who was observing the session, said the new law "puts complete authority in the hands of the president."
"I think this session was illegal. It is a kind of bloodless coup," Duaik said. "We must go back to the people to see if this session was actually legal."
Lawmakers also appointed four Fatah loyalists to key government positions — head of personnel in the Palestinian Authority, administrative chief of the parliament, head of the government's salaries and pension fund and head of the government controller.
Israeli Foreign Ministry spokesman Mark Regev declined to comment on the Palestinian parliament's actions.
Earlier Monday, Germany gave Israel support for its campaign to blacklist Hamas, which has carried out scores of deadly attacks against Israelis in recent years and is listed as a terror organization by the European Union and the United States.
"I wanted to let Israel know that it can count on our solidarity, especially after the Palestinian elections," German Foreign Minister Frank-Walter Steinmeier said after meeting acting Israeli Prime Minister Ehud Olmert. Steinmeier said his Israeli counterparts were reassured when he "made the conditions for talks (with Hamas) very clear."
Israel has grown increasingly concerned the international front against Hamas is crumbling after Russian President Vladimir Putin invited Hamas leaders to Moscow. Putin has said he will press the Palestinian group to recognize Israel and give up violence. France has supported Moscow's approach.
Hamas has given no indication it would change its ideology.
In an interview with Russia's Nezavisimaya Gazeta newspaper published Monday, Hamas' political chief, Khaled Mashaal, said the group rejected international demands to renounce violence, saying Israel must first pledge to leave all occupied lands.
A Russian diplomat, meanwhile, said Moscow understood Western concerns about Hamas but warned that cutting off international aid to the Palestinians would be "counterproductive."
"In history there are many examples of radicals coming to power and adopting a more realistic and constructive stance," Russia's ambassador to the U.N., Andrei Denisov, was quoted as saying in the Izvestia daily.
"We all hope that Hamas will show sense," he was quoted as saying.
Elsewhere, a 25-year-old Gaza woman was shot and killed Monday, Palestinian hospital officials said. Fatima Abu Musaed's family said Israeli soldiers shot her near the border fence with Gaza, the officials said.
Israeli military officials said soldiers fired warning shots in the air Monday afternoon after two people were spotted near the fence in southern Gaza.