Registration has begun for political parties contesting Cambodia's upcoming general election, with Prime Minister Hun Sen dismissing calls for a boycott of the polls by opposition figures whose party was dissolved by the pro-government courts last year.

Hun Sen in a speech Monday said the July 29 polls will proceed as planned and not be obstructed by any individuals or groups.

Sam Rainsy, the self-exiled leader of what had been the opposition Cambodia National Rescue Party, in a weekend Facebook post reiterated his group's position that voters should not cast their ballots if his party is not allowed to contest the election.

Sam Rainsy's party was the only opposition party in parliament until its lawmakers were tossed out by the court ruling that it had engaged in treasonous activities.