Cambodia’s opposition appeared to make impressive gains in Sunday’s general election, though the ruling party claimed a victory that would extend the mandate of longtime Prime Minister Hun Sen.

The results, if confirmed, lend support to opposition contentions that the vote could usher in opportunities for greater democracy in Cambodia.

Khieu Kanharith, a spokesman for the ruling Cambodian People’s Party (CPP), said on his Facebook page that his party won 68 of the 123 seats in the National Assembly. He said the opposition Cambodia National Rescue Party (CNRP) won 55 seats — gaining heavily on the 29 it held in the outgoing parliament.

The opposition party was reserving its estimates of the extent of its gains, pending the release of more figures. But even the 55 seats conceded by the ruling party represented a stunning upsurge in fortune for the CNRP, which had predicted extensive vote-rigging.

Opposition leader Sam Rainsy — who returned to Cambodia this month from years in self-imposed exile — said in a statement that it was a “historic day,” but he urged his supporters to maintain calm and wait for official results.

Provisional results from the National Election Committee were being announced Sunday night on state television, but only by individual polling stations, making it impossible to get an immediate overview of the count. It was not clear when the final official tallies would be announced.

If the results stand as the ruling party has projected, it would be a major boost for the much-
beleaguered opposition, giving it a strong platform for growth. However, a simple majority is sufficient for most legislative business, ensuring that the CPP can continue to administer the country much as it wishes, though with increased sensitivity toward public opinion. The CPP has an overwhelming majority of local administration posts as well.

Rainsy had said Saturday that although his party did not expect victory with the deck stacked against it, the election would represent a break with the past and a chance to work for “truly free and fair elections.”

Hun Sen has been in power for 28 years and says he has no intention of stepping down soon. His authoritarian rule has given him a stranglehold over the state bureaucracy that makes challenges to his authority difficult to mount.

The general election was Cambodia’s fifth since 1993, when the United Nations helped stage the country’s first free polls since the 1975-79 genocidal rule of the Khmer Rouge and a subsequent period of civil war and one-party rule.

A pressing question is how the mercurial Hun Sen will react if official results confirm that the opposition has made significant gains. He has historically accepted neither defeat nor victory with good grace.

After his party ran second in 1993, Hun Sen insisted on being named co-prime minister, then ousted his partner in government four years later in a bloody coup. He has shown a pattern of cracking down on critics after election victories in later years.

— Associated Press