Iran bans the country's two remaining official opposition parties

Iranian authorities banned the country's two remaining official opposition parties Monday after two of their leaders received prison sentences.

The move, subject to confirmation by Iran's judiciary, effectively silences the last parties legally permitted to promote political change in Iran and prevents foes of President Mahmoud Ahmadinejad from gaining power through elections.

The parties, the Islamic Iran Participation Front and the Mujaheddin of the Islamic Revolution Organization, advocated more civil liberties and changes in Iran's system of Shiite religious rule. Together they formed one of the country's main political blocs.

The action follows the sentencing Sunday of two of the parties' leading ideologues -- Mohsen Mirdamadi of the Front and Mostafa Tajzadeh of the Mujaheddin -- to six years in prison. They were also banned for 10 years from political activities after being found guilty of illegal assembly, conspiring against national security and propagating falsehoods against the state.

Both were among the leaders of young militants who seized the U.S. Embassy in Tehran in November 1979 and held 53 Americans hostage for more than a year. They backed Ahmadinejad's main challengers in Iran's presidential election last June.

Iran's main political opposition group, the Green Movement, is not a recognized party and has never had permission to operate. Its leaders, former prime minister Mir Hossein Mousavi and Shiite cleric Mehdi Karroubi, ran independently of party affiliation when they challenged Ahmadinejad in last year's election.

After Ahmadinejad was declared the winner by a landslide, Mousavi, Karroubi and the opposition parties silenced Monday charged that the election was marred by massive fraud and backed street protests against the results. 

Thomas Erdbrink @'Washington Post'