Defeated Iranian presidential candidate Mir-Hossein Mousavi rejected authorities' proposals for a partial recount of votes from this month's election and repeated his demand the entire ballot be annulled.
Iran's top legislative body, the Guardian Council, had offered to recount 10% of ballot boxes from the 12 June vote in the presence of senior officials representing the government and opposition.
Another beaten candidate, pro-reform cleric Mehdi Karoubi, also rejected the partial recount offer.
The Guardian Council has already said it found no major violations in the vote that returned president Mahmoud Ahmadinejad to power.
Mr Ahmadinejad warned today he would take a tougher approach in his second term of office to make the West regret meddling in Tehran's affairs.
He was speaking a day after US President Barack Obama praised the bravery of Iranians who protested against the election in the face of what he called ‘outrageous’ violence.
Authorities have placed responsibility for the post-election violence on Mr Mousavi, who says the vote was rigged.
His supporters staged mass protests in the week after the election, but Iranian authorities have since then used warnings, arrests and the threat of police action to drive them off Tehran's streets.
Smaller gatherings have been dispersed with tear gas and baton charges.
