* Ruling party seeks more judicial control
* Govt would have more say on appointments
* Concern about erosion of judicial independence
By Gulsen Solaker
ANKARA, Jan 8 (Reuters) - Turkish Prime Minister Tayyip Erdogan's AK Party sent plans to parliament late on Tuesday which would give the government more say over the appointment of judges and prosecutors, the latest salvo in its battle against a damaging corruption inquiry.
Erdogan has cast the graft investigation, which poses arguably the biggest challenge of his 11-year rule, as an attempted "judicial coup" contrived by an Islamic cleric, Fethullah Gulen, who exercises broad, if covert, influence in the judiciary and police.
The ruling party bill, published on parliament's official website, proposes changes to the structure of the High Council of Judges and Prosecutors (HSYK), the body responsible for appointments in the judiciary, which Erdogan has criticised since the corruption scandal erupted last month.
It allows the undersecretary of the justice minister to be elected as chairman of the HSYK board, a move which would give the government a tighter grip over the choice of judges.
"No-one should remain unsupervised. In this country, the prime minister will be supervised, ministers will be supervised, parliament members will be supervised, but not these gentlemen?" he told a rally of supporters on Dec. 29.
"This is not how it works," he said.
Erdogan and Gulen's Hizmet movement, which exercises influence through a network of contacts built on sponsorship of schools and other social and media organisations, accuse each other of manipulating the police and judiciary. Hizmet denies unleashing the corruption investigation.
The government has purged hundreds of police, among them senior commanders, since the graft scandal erupted on Dec. 17 with the detention of dozens of people including businessmen close to the government and three cabinet ministers' sons.
The battle has heightened concern about the erosion of judicial independence in Turkey, which could in the longer term also damage its bid for membership of the European Union.
Ratings agency Fitch warned on Tuesday that "strains on institutional integrity" caused by tensions between the government and judiciary were among the factors which could weaken Turkey's creditworthiness.
"All this will act as a drag on investment, growth and development, while weighing against the EU accession drive," said Timothy Ash, head of emerging markets at Standard Bank.
"The perception in the EU will be that Turkey has gone backwards over the past year or so in terms of basic EU values and principle such as democratic freedoms, the rule of law, independence of the judiciary ... This has been a gift to Turkey's opponents and critics in Europe."
(Writing by Ece Toksabay; Editing by Nick Tattersall and Ralph Boulton)