“We, as the Reform Popular Party, ran the campaign of ‘Do Not Execute Sheikh Nimr’ to prevent his execution and defend civil rights,” Mohammad Zare Foumani, the secretary general of the party, told the Tasnim News Agency.
He added that his party has also sent letters to some human rights organizations, requesting them to help prevent the execution of the Saudi cleric.
The campaign came after unnamed European diplomatic sources said Saudi Arabia intends to carry out the death sentence of Sheikh Nimr on May 14.
Human rights activists have urged the Al Saud regime to immediately revoke Sheikh Nimr's death sentence and release him.
Back in early March, a Saudi Arabian appeal court approved the death penalty of the prominent cleric.
Sheikh Nimr was detained in July 2012 following demonstrations that erupted in the country's Qatif region. He is accused of delivering anti-regime speeches and defending political prisoners.
His arrest sparked widespread protests in the Arab country. In October 2014, Sheikh Nimr's family reported that a Saudi judge has found him guilty of "sedition" and sentenced him to death.