US Democratic Senator Ben Cardin, chairman of the Senate Foreign Relations Committee, is refusing to move forward with a bill sanctioning Iran's leaders.

The bipartisan Mahsa Amini Human rights and Security Accountability Act (MAHSA Act) sanctions the Supreme Leader and the President of the Islamic Republic, among others, for their role in human rights abuses.

It passed the House of Representatives with overwhelming majority in September 2023, but has not yet been marked up for a vote in the Senate.

Iranian-American activists –who have been chasing Cardin for months to no avail– say they will stage a peaceful protest at the senator’s office next week, hoping to highlight “the importance of holding the leaders of the Islamic Republic in Iran accountable.”

The MAHSA Act is named after a 22-year-old Iranian woman who was detained in September 2022 for not covering her hair as much as the authorities deem enough. She received fatal head injuries while in custody and died in hospital shortly after.

Her death sparked the most widespread anti-regime protests in decades. Across Iran, the security forces and plain clothed thugs attacked people, killing more than 550 and injuring thousands.

The MAHSA Act was first introduced to the US House of Representative in January 2023 and passed with broad bipartisan support.

It’s unclear why Senator Cardin is blocking the bill to go up for a full vote in the Senate. His stance seems in line, however, with the Biden administration’s Iran policy –which some critics have called “appeasement” in pursuit of some kind of nuclear agreement.