Cambodia's Constitutional Council has affirmed the decision to disqualify the country's leading opposition party from participating in the general elections in July.

The Candlelight Party, a weakened reincarnation of a popular opposition party that was dissolved in 2017, was disqualified from the July election 10 days ago over an issue with its registration paperwork.

The decision announced on Thursday means the ruling Cambodian People's Party (CPP) will run largely unopposed.

The general elections scheduled on July 23 will be held to elect members of the National Assembly.

The tribunal' s president Chhun Lim at a press conference said the appeal was deemed not legal and the decision was final.

The Candlelight Party was disqualified from the election on May 15 for submitting a registration document that was a photocopy rather than an original.

Rights groups have expressed outrage over what they call an attempt by Prime Minister Hun Sen to crush his democratic opposition. He has ruled Cambodia for more than 38 years and is considered as Asia's longest-serving leader.

Officials from the Candlelight Party could not immediately be reached for comment on the tribunal's decision.

Just over a year old, Candlelight was the only party running against Hun Sen's ruling CPP, since the 2017 dissolution of its popular rival, the Cambodia National Rescue Party (CNRP).

Scores of former CNRP members have been detained or convicted of crimes, many in absentia having fled into exile.

Hun Sen has previously said the CPP will dominate politics for up to 100 years.