Cambodia's election committee has disqualified the largest opposition Candlelight Party from participating in general elections in July.

The committee said on Monday that the Candlelight Party -- a major challenger against Prime Minister Hun Sen's ruling party -- would not be allowed to contest the polls, since it failed to submit necessary documents.

The Candlelight Party is an apparent successor to the defunct Cambodia National Rescue Party, which was forced to disband before the previous general polls. It gained the second largest share of the votes in last year's local elections, after Hun Sen's ruling party.

The decision to disqualify the Candlelight Party is seen as part of efforts by the government to remove major challengers. Experts say this looks like what the government did ahead of general elections five years ago.

Western countries are concerned that the latest development could be a major setback to Cambodia's democracy. Hun Sen's government has continued its crackdown on critics for nearly four decades. Japan has long helped the country hold democratic elections following the end of its civil war.