PHNOM PENH (REUTERS) - Cambodia's parliament endorsed opposition leader Sam Rainsy on Friday as minority leader with legislative rank equal to Prime Minister Hun Sen, a rare concession by the long-serving premier to preserve a fragile political truce.

The arrangement is part of a deal struck in July to end the Cambodia National Rescue Party's (CNRP) parliamentary boycott and break a year of deadlock fraught with street protests, factory strikes and sporadic unrest resulting from a 2013 election the opposition said was rigged.

CNRP president Sam Rainsy said his stronger house role would foster a "new culture of dialogue" with Hun Sen, his long-time political nemesis. "This is a very important political turning point," the French-educated Sam Rainsy told reporters after the parliamentary session. "Before, the ruling party has always tried to get rid of the opposition party. The culture of getting rid of each other even led to some violence."

Sam Rainsy's new position and the appointment of CNRP's Kem Sokha as deputy house speaker in August reflect the opposition's newfound power amid growing public discontent with Hun Sen's dominant Cambodian People's Party (CPP), which critics say has abused the power it gained in polls won on populist platforms.

The CNRP won 55 seats to the CPP's 68 in a disputed 2013 poll, on promises to halt land grabs and raise factory wages, a result experts say caught the ruling party off guard and pushed it towards what are unprecedented compromises.

The political crisis saw security forces crack down violently on garment workers protesting for better pay, who had sided with CNRP after it promised to raise incomes.

The unrest alarmed major clothing brands that outsource manufacturing to Cambodia, among them Nike, Gap and Adidas.

Independent analyst Ou Virak said recognition of Sam Rainsy as a legislative equal was little more than a gesture by Hun Sen that would not boost the opposition's bargaining power. "Making the new post equal 'in rank to prime minister' but with no real power is a tactic used successfully by Hun Sen many times before," Ou Virak said.

"This is yet another example of form over substance. Cambodia is also obsessed with hierarchy, a place to sit according to the rank."