(CNN) -- Iranian opposition leader Mir Hossein Moussavi plans to form a new political party aimed at reining in the power of the Islamic Republic's leadership, a leading reformist newspaper reported Sunday.
Mir Hossein Moussavi is reportedly seeking to form a new political party in Iran.
Moussavi told supporters the party will be focused on upholding "the remaining principles of the constitution," according to Etemad-e Melli, a newspaper aligned with fellow opposition candidate Mehdi Karrubi.
He is expected to file papers with Iran's Interior Ministry to establish the party before hard-line incumbent Mahmoud Ahmadinejad is sworn in for a new term, the newspaper reported.
The announcement comes after weeks of protests over Iran's disputed presidential election and an attempted clampdown by Iran's clerical leadership.
The clerical leadership has declared Ahmadinejad the winner of that vote. Moussavi, a former prime minister, was the leading challenger to Ahmadinejad in the June 12 balloting.
The official results showed Ahmadinejad winning with more than 62 percent of the vote. Moussavi and Karrubi have consistently rejected those results as fraudulent and demanded a new vote.
Their supporters turned out in crowds estimated in the hundreds of thousands to demand the results be overturned.
Iran's Guardian Council, which oversees the elections, has declared the official count will stand.