Britain's relations with Iran have worsened with the tit-for-tat expulsions of diplomats from each other's embassies. Iran, which has singled out Britain for blame for the unrest on the streets of Tehran in the wake of the disputed presidential election, ordered two British diplomats to leave the country. The regime accused the pair of "activities inconsistent with their diplomatic status" - usually code for spying, a claim which Prime Minister Gordon Brown said was "entirely without foundation". Tehran's actions led to the immediate retaliatory expulsions of two Iranian diplomats by the UK. Mr Brown told MPs the Government would "continue to seek good relations with Iran and to call for the regime to respect the human rights and democratic freedoms of the Iranian people". But he said the two Iranian officials had been ordered to leave the country as a direct response. Both sets of diplomats have been given a week to pack their bags. Conservative leader David Cameron said the expulsion of the British diplomats was "clearly not acceptable" and backed the retaliatory measure. The Foreign Office said the Iranian decision was "baseless" and appeared to be part of policy of blaming Britain - which its spiritual leader last week named "the most evil" of Western nations - for the unrest. A spokesman said: "We think the Government of Iran is seeking to blame the UK and other outsiders for what is an Iranian reaction to an Iranian issue. "This has a potential impact on our staff safety and is unacceptable. We have taken the decision to reciprocate." The dependants of British diplomats are already being evacuated from the Iranian capital and the Foreign Office advises against all but essential travel to the country. Before announcing the retaliatory move, Mr Brown defended his decision to speak out in the wake of the violence meted out to demonstrators in the Iranian capital. "When there is a sign of repression or where there is violence that's affecting ordinary people in the streets we have a duty to speak out and to say we want Iran to be part of the world, we don't want Iran to be isolated from the world," he said. "But that requires Iran to say it's taking seriously these issues we are raising with them and other countries are raising with them."