* Some ministers, deputies voice support for president's view
* Erdogan calls for law to be returned to president unchanged
* Speculation about strains with Islamic movement
By Daren Butler
ISTANBUL, Dec 8 (Reuters) - Rare dissent surfaced within Turkish Prime Minister Tayyip Erdogan's ruling AK Party this week after the president vetoed a new law on match-fixing, raising questions about party unity as its leader recovers from surgery.
The dispute emerged after President Abdullah Gul last week sent back to parliament a revised law reducing jail sentences for those guilty of manipulating soccer matches, a measure coinciding with a nationwide investigation into match-rigging.
An Istanbul court will decide later this month whether charges against 93 accused, including the chairman of champions Fenerbahce and a deputy president of the Turkish Football Federation, have sufficient evidence to warrant going to trial.
The legislation would cut jail terms to up to 3 years from 12 years, amending a law which only went into effect in April.
Erdogan, 57, is recovering at home in Istanbul from abdominal surgery nearly two weeks ago and his absence has resulted in the cancellation of two cabinet meetings.
It has also fuelled media speculation on what would happen if Erdogan were to withdraw from politics after shaping the political landscape for the last decade. The health minister said on Thursday Erdogan was in good health.
Gul, a leading member of the party before he left to become president, said the proposed changes encouraged the view that the law was designed to benefit particular people.
"The impression was created in public opinion that the reform was directed at individuals involved in an ongoing investigation rather than emerging out of necessity," Gul said.
It is a rare disagreement between the AKP and Gul, who is expected to return to active politics if Erdogan seeks the presidency as expected in 2014.
Most of the country's leading clubs were named in the indictment. And more than 30 players and officials have been in jail pending trial since the scandal broke in July, throwing the domestic multi-billion dollar league into turmoil.
AK Party lawmakers are standing their ground in a clear challenge to Gul, vowing to send the law back to him unchanged. The two main opposition parties back the AKP position.
If that view prevails, as appears likely, Gul would be obliged to approve the law. He could send the law to the constitutional court but that is regarded as unlikely.
A parliamentary commission was set to approve the law on Thursday before a debate in the general assembly on Sunday and would then send it back to the president.
"I personally share exactly the opinions, legal view and rationale of the president," said Deputy Prime Minister Bulent Arinc, saying he doubted MPs would challenge Gul.
"I think that given the public pressure on this issue, no deputy will have the courage to bring this law back to parliament's general assembly," Arinc said.
But on hearing Arinc's comments, Erdogan told ministers the law should be sent back to the president unchanged if it has the support of other parties, media reports said.
STRAINS BETWEEN AKP, GULEN?
Advocates of the tougher original law regard it as part of a broader campaign to clean up Turkish society, saying it would be wrong to trivialise sports-related felonies since they involved organised crime and large sums of money.
Veteran commentator Mehmet Ali Birand said the powerful Islamic Gulen movement, headed by self-exiled, Pennsylvania-based theologian Fethullah Gulen, opposed softening the law and said there was speculation of tension between Gulen and the AKP.
"The latest match-fixing law is creating a difference of opinion between the two sides. The (Gulen) community is not in favour of the law being softened. The stance of President Gul is being supported. This is irritating AK Party people," Birand said in a column in the Posta newspaper.
He added however that the Gulen movement, which has been close to Erdogan's party since before it came to power in 2002 was not expected to withdraw support for the party.
The Zaman newspaper, closely tied to the Gulen movement, highlighted opposition to the law within the AKP, naming three other deputies who are critical of the revised law. One of them has threatened to resign if the amended law is passed.
"AK Party stance on match-rigging amendment sparks outrage," said the front-page headline in the English-language Today's Zaman newspaper on Thursday. (Writing by Daren Butler; Editing by Jon Hemming)