The movement is not a political party — which would require a government permit — but a “grass-roots and social network” that will promote democracy and adherence to the law, Mr. Moussavi wrote in a statement on his site. It is to be known as the Green Way of Hope, in deference to the signature bright green color of his campaign for the June 12 presidential election, which he maintains was rigged in favor of President Mahmoud Ahmadinejad…

In his announcement, Mr. Moussavi countered efforts to portray him as a tool of secular foreigners, affirming his support for institutions like the Revolutionary Guards and the Basij militia, despite the fact that they are widely believed to be in charge of the current crackdown. But he also lashed out at the recent threats aimed at him and his supporters, saying, “Instead of accusing this millions-strong group, you should look to those who have created a poisonous propaganda war that served the interests of the enemy.”