* Pro-Kurdish party slams ruling as double standard
* MP from main opposition party released last week
* Ruling could undermine confidence in peace process (Adds quotes, background)
By Seyhmus Cakan
DIYARBAKIR, Turkey, Dec 16 (Reuters) - A Turkish court on Monday rejected bids by two Kurdish lawmakers to be released from lengthy pre-trial detention, a move that could undermine confidence in a fragile peace process with Kurdish militants.
The decision by the court in Diyarbakir, the regional centre of Turkey's mainly Kurdish southeast, came despite the country's top court ruling this month that the long-term detention of another MP pending trial was unconstitutional.
Gulser Yildirim and Ibrahim Ayhan, members of parliament for the Kurdish Peace and Democracy Party (BDP), were detained in 2010, charged with links to the militant Kurdistan Workers Party (PKK) and are still held pending trial verdicts.
The Turkish state began peace talks with the PKK - designated a terrorist group by Turkey, the United States and the European Union - more than a year ago to try to end a three-decade conflict which has killed more than 40,000 people.
The release of prisoners accused of links to the PKK has been a long-standing Kurdish demand.
The BDP described the court ruling as a "legal scandal" and said the judiciary was showing an openly hostile attitude towards the deputies.
"It is a political decision, a decision which disregards completely the public will and the right to conduct democratic politics," the party's joint leaders Selahattin Demirtas and Gultan Kisanak said in a statement.
The party demanded the immediate release of the jailed deputies, among thousands being prosecuted in related court cases, and denounced "political prosecutions".
"In town squares our people will give their response to this decision which disregards their will in the best possible way," the statement said.
The government says the judiciary acts independently in such cases.
A ceasefire with the PKK has largely held since March and the government has proposed a package of limited reforms aimed at bolstering democracy, but PKK commanders have warned of renewed violence unless the process progresses.
Four Turkish soldiers were briefly seized by PKK militants this month and there have been violent clashes between security forces and protesters, exacerbated after the killing of two demonstrators in Yuksekova near the Iranian border 10 days ago.
"This decision will be a serious problem for the peace process, tensions will increase and the people will not accept it," deputy BDP leader Meral Danis Bestas told Reuters.
Three other BDP deputies in detention have also requested release but a prosecutor at a second court in Diyarbakir recommended on Monday that their petitions be turned down.
Hopes for the Kurdish parliamentarians' release had been heightened when an MP from another opposition party was freed last week after the Constitutional Court ruled his pre-trial detention had violated his rights.
Mustafa Balbay of the main opposition Republican People's Party (CHP) pledged his oath in parliament last Tuesday after he was released pending appeal from nearly five years in prison on conspiracy charges.
He was among 275 defendants including an ex-military chief, retired officers, academics, journalists and politicians jailed in August over an alleged plot to overthrow Prime Minister Tayyip Erdogan's Islamist-rooted government. (Additional reporting by Gulsen Solaker; Writing by Daren Butler; Editing by Nick Tattersall and Ralph Boulton)