Leading Iran reformist Mostafa Tajzadeh, who has made repeated public calls for "structural changes" to the Islamic republic, has been jailed for five years, his lawyer said late Tuesday.

The 65-year-old, who was arrested on July 8, before the wave of protests triggered by the death in morality police custody last month of Mahsa Amini, has begun serving his sentence after choosing not to appeal, lawyer Houshang Pourbabai said on Twitter.

"My client Mostafa Tajzadeh was sentenced to five years for plotting against state security, two years for publishing lies and one year for propaganda against the system," Pourbabai said.

He said the jail sentences would run concurrently, so his client would serve five years in prison.

Tajzadeh refused to put up any defence at his trial, which opened on August 13, after the court denied him permission to consult privately with his lawyer.

Tajzadeh's wife Fakhrossadat Mohtashamipour, who is also a leading reform activist, expressed concern that her husband was being held in solitary confinement despite his ill health.

A former government minister under the presidency of Mohammad Khatami, a reformist who oversaw a rapprochement with the West between 1997 and 2005, Tajzadeh already spent seven years in prison.

He was jailed with other reformist leaders after the re-election of hardline president Mahmoud Ahmadinejad sparked mass protests in 2009.

Tajzadeh registered to stand on a reform platform in last year's presidential election but, like most other reformist hopefuls, his candidacy was rejected by the Guardian Council, which vets all candidates for public office.

In his campaign material, Tajzadeh billed himself as a "citizen, a reformist," and a "political prisoner for seven years".

He hit out out against "blocks on the internet", "interference by the military in politics, the economy and elections" and a "costly and pro-Russian foreign policy driven by anti-Americanism".