TEHRAN - Iran ruled out cancelling the disputed presidential vote on Tuesday, issuing a new warning to the leader of the opposition and lashing out at UN "meddling" as it battles the most serious challenge to the Islamic regime in 30 years.

As international alarm over the crisis mounted, Britain said it was expelling two Iranian diplomats after a similar move by Tehran while other European nations hauled in envoys to protest at the election and the repression of the opposition protests.

But the top election watchdog, the Guardians Council, insisted the vote would stand.

"We witnessed no major fraud or breach," spokesman Abbasali Kadkhodai said on English-language state television Press TV. "Therefore, there is no possiblity of an annulment taking place."

The opposition has been staging almost daily rallies to protest at alleged fraud and widespread irregularities in the June 12 election which returned hardline President Mahmoud Ahmadinejad to power for another four years.

Mir Hossein Mousavi, the opposition leader who was defeated by a landslide according to official results, plans to issue a "full report of electoral fraud and irregularities," a statement posted on his official website said.

But the interior ministry warned Mousavi, who was premier in the post revolution era, "to respect the law and the people's vote" after his presidential election defeat, the state-run IRNA news agency said.

World leaders are calling for an immediate halt to state violence against the protesters, but the Iranian authorities have fired back, accusing Western governments particularly Britain and the United States of interfering.

In the latest outburst, the foreign ministry took aim at UN chief Ban Ki-moon over remarks it said smacked of "meddling" in its affairs, the state broadcaster reported.

"These stances are an evident contradiction of the UN secretary general’s duties, international law and are an apparent meddling in Iran’s internal affairs," ministry spokesman Hassan Ghashghavi said

"Ban Ki-moon has damaged his credibility in the eyes of independent countries by ignorantly following some domineering powers which have a long record of uncalled-for interference in other countries’ internal affairs and colonisation," he said.

On Monday, Ban called on the Iranian authorities to stop resorting to arrests, threats and the use of force against civilians.

The state media said at least 17 people have been killed and many more wounded in the unrest that has convulsed the nation for 11 days, shaking the very pillars of the Islamic republic.

Hundreds of protestors and prominent reformists and journalists have been rounded up by the authorities -- even figures close to top regime officials including former president and powerful cleric Akbar Hashemi Rafsanjani.

In the latest crackdown on the media, Iran has arrested a journalist of Greek origin working for the Washington Times, the Fars news agency said.

"I call on foreign reporters to work within our laws when travelling to Iran for news coverage... because if they act against national security and spy, they will be arrested by security institutions and handed over to the judiciary," culture ministry official Mohsen Moghadaszadeh warned.

Foreign media have been restricted in their reporting of the crisis, with bans on covering demonstrations, and some Western outlets have been accused of fomenting the violence and acting as the "mouthpiece of rioters."

Iran has already expelled the BBC's Tehran correspondent and ordered the closure of Al-Arabiya television's office while Newsweek said a Canadian journalist working for the magazine has been detained without charge.

The streets of Tehran remained tense the day after hundreds of riot police armed with steel clubs and firing tear gas, backed up by the Basij Islamic militia, broke up an opposition rally of about 1,000 people.

Demonstrators had gathered in defiance of the Revolutionary Guards, the elite force set up in the wake of the 1979 revolution, which warned of a "decisive and revolutionary" riposte to protests.

The 27-member European Union on Monday rejected Iran's claims of interference as "baseless and unacceptable" but voiced deep concern about the continuing violence.

And in the latest European moves, France, Finland and Sweden summoned the Iranian ambasadors in their capitals, with Paris protesting at the "brutal repression" of demonstrators.

Iran has singled out Britain, as well as the United States, as one of the leading instigators of the post-election unrest, with supreme leader Ayatollah Ali Khamenei last week describing it as the "most evil" of its enemies.

An Iranian lawmaker was quoting as saying by the official IRNA news agency that Tehran's ambassador to London would be recalled for consultations, but this was later denied by a foreign ministry source to AFP.

London is pulling out families of embassy staff and, along with some other European nations, warned its nationals against travel to Iran.

But student unions cancelled a planned demonstration outside the British embassy in Tehran after the interior ministry said it would not issue a permit.

Mousavi has urged his supporters to continue demonstrating but to adopt "self-restraint" to avoid more bloodshed.

Defeated reformist candidate Mehdi Karroubi called for a ceremony on Thursday to mourn slain protesters.

The Guardians Council, which has acknowledged there were more votes cast than eligible voters in 50 of 366 constituencies, is due to make its final ruling on Wednesday.

The defeated challengers have listed 646 irregularities and are insisting on a new election, not a recount.

But parliament said it was preparing for the new government to take office.

"Parliament's board of directors set July 26 to August 19 as the period for the president's swearing-in and the introduction of the new cabinet," IRNA said.

Despite the media restrictions, images of police brutality have spread worldwide via amateur video over the Internet.

Dramatic footage of the final moments of Neda Agha-Soltan, a young woman whose death during protests in Tehran has made her a symbol for the opposition, has been flashed around the world.