Sam Rainsy, recently-pardoned leader of the Cambodia National Rescue Party (CNRP), was ineligible to vote or run as a parliamentary candidate for the July 28 national polls, Tep Nytha, secretary general of the National Election Committee, said Thursday.

"According to the law, Sam Rainsy can neither vote nor stand as a candidate for the upcoming polls because the voter lists and political party candidate lists have already been officially recognized by the National Election Committee," he told reporters.

Sam Rainsy's name was deleted from the voter registry since November on the grounds that he was a convicted criminal with an 11-year prison sentence.

On Friday last week, King Norodom Sihamoni granted the charismatic opposition leader a royal pardon, allowing him to return to Cambodia after nearly 4 years abroad in a self-imposed exile.

Tep Nytha said that with the royal pardon, Sam Rainsy is free to campaign for his party in the upcoming polls even though he cannot vote or run as a candidate.

The United Nations Special Rapporteur on the situation of human rights in Cambodia, Surya P. Subedi, on Monday urged the government of Cambodia to "take the necessary action" to allow Sam Rainsy to play a "full role" in the Cambodian politics.

Dr. Sok Touch, deputy director general of the Royal Academy of Cambodia's International Relations Institute, said that in a political aspect, Sam Rainsy should be eligible to stand as a candidate for the polls, or the opposition party and international community will probably not recognize the results of the election if the opposition loses.

"In my point of view, if Sam Rainsy is ineligible to run in the election, this can be an excuse for the opposition to denounce the results of the upcoming polls when it loses," he told Xinhua.

Sam Rainsy announced to return to Cambodia on Friday this week. The party's spokesman Yim Sovann said more than 40,000 supporters will hold a rally at the capital's airport to greet him.

Eight political parties are contesting in the upcoming elections with about 9.67 million eligible voters.

Two main parties are the Cambodian People's Party of longtime Prime Minister Hun Sen and the opposition party of Sam Rainsy.

Hun Sen's party is widely expected to win the majority vote in the forthcoming elections.

One of the world's longest-serving leaders, Hun Sen, 61, has been in power for 28 years and vowed to stay in the post until he's 74.

In the last elections in July 2008, Hun Sen's party won 90 seats out of the 123 seats in the National Assembly, while the opposition group totally gained 29 seats.