PKK rebels say scrap ceasefire on Turkish forces

* PKK guerrillas blame lack of political progress

* Seeking greater rights for Turkey's Kurds

ARBIL, Iraq, June 3 (Reuters) - Kurdish militants from the Kurdistan Workers Party (PKK) have scrapped a year-old unilateral ceasefire and resumed attacks against Turkish forces, a PKK spokesman said on Thursday.

The move follows an escalation in violence with the onset of summer between Turkish armed forces and PKK guerrillas fighting from bases in the semi-autonomous Kurdistan region of northern Iraq. "Two days ago, we started waging attacks against the Turkish army in response to their repeated military attacks against the party and political attacks facing Kurds in Turkey," PKK spokesman Ahmed Danees told Reuters in Kurdistan.

"We have decided to break the unilateral ceasefire with Turkey that we announced in April last year."

He blamed a lack of progress on a political reform package announced last year by the Turkish government, and military operations of the kind late last month when Turkish warplanes attacked some 50 PKK targets in northern Iraq.

The PKK announcement coincides with a landmark visit to Turkey by Iraqi Kurdish leader Massoud Barzani, underscoring deepening trade ties between Turkey and Iraqi Kurdistan.

The ceasefire has long been on shaky ground.

Violence has risen following the spring thaw. Turkish authorities have said the PKK's attacks this spring include remote-controlled bombs, ambushes on military bases and firefights.

Officials have said May was the deadliest month this year, with 23 soldiers killed and 33 wounded.

More than 40,000 people, mostly Kurds, have been killed since the PKK took up arms against Turkey in 1984 for an independent homeland. The rebels say they now want greater rights and autonomy for Turkey's estimated 15 million Kurds.

Fighting has dropped off since Turkish agents snatched guerrilla leader Abdullah Ocalan from Kenya in 1999.

But relentless army operations against the PKK inside Turkey's mainly Kurdish southeast and periodic military raids into northern Iraq have failed to extinguish the insurgency.

The PKK, branded terrorists by Turkey, the United States and the European Union, declared a "period of non-action" in April 2009, saying they would halt fighting except in self-defence.

The gesture coincided with a pledge by the Turkish government of Prime Minister Tayyip Erdogan to expand Kurdish rights under a reform package designed to end the conflict.

But the initiative suffered a setback in December, when the Constitutional Court outlawed the Democratic Society Party (DTP) on charges of being the political wing of the PKK.

"... they have not presented any real projects that might aid the Kurdish issue since the announcement of the last constitutional reform package of the government," Danees said.

"We find ourselves compelled to defend ourselves, to protect our people and our national question in Turkey," he said. (Additional reporting by Ayla Jean Yackley in Istanbul, writing by Suadad al-Sahly and Matt Robinson in Baghdad)