* Opposition has enough MPs to force recall of parliament
* Parliament in recess because of March 30 local elections
* Erdogan says graft claims baseless, aimed at ousting him
By Gulsen Solaker
ANKARA, March 13 (Reuters) - Turkey's opposition demanded on Thursday a recall of parliament to hear corruption allegations against four former ministers in a move which could spell further trouble for Prime Minister Tayyip Erdogan ahead of local elections on March 30.
Erdogan has cast the graft scandal as a plot to smear him by Islamic cleric Fethullah Gulen, a U.S.-based former ally with influence in Turkey's police and judiciary. Erdogan has responded to the scandal by reassigning thousands of police officers and hundreds of judges and prosecutors.
Social media has been awash with snippets of leaked wiretap recordings presented as evidence of wrongdoing, but the purge of police and judiciary has brought investigations to a virtual halt and few specifics on the core allegations have leaked out.
Police documents on the four ex-ministers were sent to parliament in late February and a summary would usually be read out on the floor. However, the assembly went into recess for the election campaign period shortly afterwards and the files have been kept under lock and key ever since.
Mehmet Akif Hamzacebi, a senior deputy from the main opposition Republican People's Party (CHP), told a news conference on Thursday his party had filed a parliamentary petition with 132 signatures for the assembly's recall.
"The parliamentary speaker has no option other than to have the records read and present the additional dossiers and documents to deputies," Hamzacebi said, adding that failure to accept the petition would violate Turkey's constitution.
Under parliamentary rules, speaker Cemil Cicek, who is a member of Erdogan's centre-right AK Party, has a week to summon the assembly for an extraordinary session.
A recalled session requires the attendance of at least 184 deputies in the 550-member assembly, which the CHP could achieve with the support of the nationalist MHP and pro-Kurdish BDP parties. Both have said they would back the move.
The police records concern former interior minister Muammer Guler, former environment minister Erdogan Bayraktar, former EU affairs minister Egemen Bagis and former economy minister Zafer Caglayan, all of whom have left their cabinet positions since the corruption scandal erupted on Dec. 17.
The ministers deny any wrongdoing.
The AK Party is expected to try to block a recall of parliament which could see details of the allegations made public just days ahead of municipal polls, widely seen in Turkey as a referendum on Erdogan's leadership.
The party, which has presided over more than a decade of rising living standards in Turkey, remains well ahead of its rivals in opinion polls despite the corruption scandal. (Reporting by Gulsen Solaker; Writing by Daren Butler; Editing by Nick Tattersall and Gareth Jones)