(Corrects spelling of name of analyst Ghanem Nuseibeh)
* Rival Arab powers compete to secure Gaza truce
* Gaza shows extent of rift carved by regional turmoil
* Egypt, Qatar are main Arab protagonists in ceasefire talks
By Amena Bakr, Yasmine Saleh and Shadia Nasralla
DOHA/CAIRO, July 21 (Reuters) - The push for a Gaza ceasefire risks becoming mired in a regional tussle for influence between conservative Arab states and Islamist-friendly governments, with rival powers competing to take credit for a truce, analysts and some officials say.
The main protagonists are Arab heavyweight Egypt and the tiny Gulf state of Qatar, on opposite sides of a regional standoff over Hamas, the Islamist group that controls the Gaza Strip, and its ideological patron the Muslim Brotherhood.
Both camps suggest the other is motivated as much by a desire to polish diplomatic prestige and crush political adversaries as by the humanitarian goal of protecting Palestinian lives from the Israeli military.
"Gaza has turned very suddenly into the theatre in which this new alignment within the Arab world is being expressed," said UK-based analyst Ghanem Nuseibeh.
"Gaza is the first test for these new alliances, and this has affected the possibility of reaching a ceasefire there."
He was referring to Qatar, Turkey, Sudan and non-Arab Iran, the main members of a loose grouping of states which believe Islamists represent the future of Middle East politics.
That camp stands in increasingly overt competition with a conservative, pro-Western group led by Egypt, Jordan, the United Arab Emirates and Saudi Arabia, most of whom are intent on crushing the Brotherhood and see it as a threat.
That cleavage is now apparent in the diplomacy over Gaza.
Qatar bankrolled the elected Muslim Brotherhood government of Egyptian President Mohamed Mursi, who was overthrown by the military a year ago. Saudi Arabia and the UAE have since poured in money to support strongman Abdel Fattah al-Sisi, who led the takeover and has since been elected president after outlawing and suppressing the Brotherhood.
Under his rule, Egypt has tightened its stranglehold on the southern end of the Gaza Strip, closing tunnels to try to block supplies of weapons and prevent militants crossing.
Egyptian officials suspect Qatar encouraged Hamas to reject a ceasefire plan Cairo put forward last week to try to end an Israeli assault that has now killed more than 500 Palestinians as well as 18 Israeli soldiers and two Israeli civilians.
Palestinian officials said the proposal contained little more than Israeli and U.S. terms for a truce. Hamas has its own demands for stopping rocket fire into Israel, including the release of prisoners and the lifting of an economic blockade.
With Egypt's initiative sidelined, all eyes turned to Doha, where visiting Palestinian President Mahmoud Abbas on Monday met Hamas leader Khaled Meshaal, who lives in the Qatari capital, a senior Qatari source told Reuters.
An official in Cairo said the Gaza battle "is part of a regional conflict between Qatar, Egypt and Turkey.
"Hamas ... ran to Qatar, which Egypt hates most, to ask it for intervention, and at the end we are sure Hamas will eventually settle with an agreement that is so similar to a proposal that Egypt had offered, but with Doha's signature."
U.S. Secretary of State John Kerry, due in Cairo late on Monday, is likely to have to mediate between Egypt and Qatar in a bid to end the fighting in Gaza.
"The dilemma is now to get Egypt and Qatar to agree. It is obvious that Hamas had delegated Qatar to be its spokesman in the talks," said an Egyptian diplomat. "Kerry is here to try to mediate between Qatar and Egypt to agree on a deal that Hamas would approve."
Another foreign ministry source said: "Egypt will be asked by Kerry to add in Hamas' conditions and then Kerry will go to Qatar and ask it to ask Hamas to approve the amended deal."
For reasons of history and geography, Egypt has always seen itself as the most effective mediator in the Israeli-Palestinian conflict in neighbouring Gaza.
But critics say Egypt's strongly anti-Islamist government is trying to pressure Hamas into accepting a truce offering few concessions for the group. Its aim, they say, is to weaken the movement and allied Islamist forces in Egypt.
Hamas leaders said they were not consulted on the Egyptian move, and it did not address their demands.
With peace efforts delicately poised, Gaza now appears to be a test of strength in a regional struggle for power.
Emirati political scientist Abdulkhaleq Abdulla said Gaza mediation had seen "a lot of political interference".
"Qatar was unhappy with the Egyptian ceasefire (plan). They are very uncomfortable that it came from Egypt. The Qataris are trying to undermine Egypt politically, and the victim is the ceasefire that Egypt has proposed.
"The terms of the problem is -- who will present the ceasefire? Who will win the first political match between those two new camps within the Arab world?" Abdulla said.
At the root of the rift are opposing attitudes to the Muslim Brotherhood, which helped sweep Hosni Mubarak from power in Egypt in 2011 only to be ousted itself last year.
Its ideology challenges the principle of conservative dynastic rule long dominant in the Gulf: Some of its leading members are based in Qatar and broadcast their views via the country's media, angering other Gulf Arab states
Qatar is accused of using its alliance with Hamas to elbow its way into efforts to mediate between the movement and Israel.
Critics suspect Qatar wants to repair an international image clouded by months of allegations of poor labour rights, alleged corruption over the 2022 World Cup and political tensions with its Gulf Arab neighbours.
But Western governments see Qatar, maverick though it be, as a potentially significant regional mediator because of its links to Islamist movements in Egypt, Syria and elsewhere.
Qatar denies any ulterior motive and notes that Washington has openly asked it to talk to Hamas. Foreign Minister Khaled al-Attiyah said on Sunday Qatar's role was just to facilitate communication.
"BLOODSHED NEEDS TO STOP"
A source familiar with the matter said Qatar will not press Hamas to change or reduce its demands.
In Saudi Arabia, where suspicion of Hamas is particularly strong, as an ally of the Brotherhood and of Iran, Riyadh's main regional adversaries, newspapers have abandoned a tradition of blaming Israel alone to also attack the Palestinian group.
"The Hamas leadership, from Egyptian blood to Palestinian blood," was the headline of an opinion article by Fadi Ibrahim al-Dhahabi in the daily al-Jazeera newspaper on Sunday.
He argued that Hamas was stoking the war in Gaza not for the sake of Palestinian liberation, but as part of a wider Muslim Brotherhood campaign against Egypt's government and to win favour with Iran.
Palestinian negotiator Saeb Erekat, part of a recently formed national unity government intended to overcome rivalry between Hamas and the more secular Fatah nationalist movement, told Reuters he had seen no tug-of-war among Arab states.
"This is not the case. There is no competition between Arab countries, they all want to stop the bloodshed," he said.
"All Arab countries want to bring an end to this fountain of blood in Gaza, Turkey, Qatar and Egypt are all in agreement. And the leaders of these country's have put their differences aside and all agree that the bloodshed needs to stop". (Additional reporting by William Maclean and Angus McDowall, Writing by William Maclean, editing by Paul Taylor)