(Adds quotes, background)
TEHRAN, June 15 (Reuters) - Defeated Iranian presidential candidate Mirhossein Mousavi is not optimistic about his appeal to a legislative body for the cancellation of last week’s election result, his website said on Monday.
Citing voting irregularities, Mousavi formally demanded on Sunday that the June 12 election be annulled after the Interior Ministry released results showing hardline President Mahmoud Ahmadinejad had won by a landslide.
"I have appealed to the Guardian Council but I‘m not very optimistic about their judgment," his website quoted him as telling supporters at a rally in downtown Tehran on Monday.
"Many of its members during the election were not impartial and supported the government candidate," he said.
Many tens of thousands of people gathered for the pro-Mousavi rally, defying a government ban. The Interior Ministry had warned that Mousavi would be responsible for any consequences if he went ahead with a gathering.
At the end of the rally, hardline Islamic Basij militiamen killed one person and wounded more when their building was attacked by people in the crowd, an Iranian photographer said.
Mousavi, speaking before the shooting, said he was "ready to pay any price" in his fight against election irregularities.
"I came here to invite everyone to defend their rights calmly," he said.
Saturday’s announcement of the election result sparked violent protests in Tehran and elsewhere, as anti-Ahmadinejad demonstrators clashed with riot police and Basij members.
"I‘m urging government forces to stop violence against people," Mousavi said. (Reporting by Parisa Hafezi; writing by Fredrik Dahl; editing by Alison Williams)