Iran today warned it was "reconsidering" its relationship with Britain.
Iran accuses Britain and other Western nations of fomenting the post-election turmoil that has shaken it.
Britain has condemned the fierce crackdown on the Iranian opposition following the disputed June presidential election.
Foreign Minister Manouchehr Mottaki said the ties have been under detailed scrutiny and a "magnifying glass" over the past six months, but did not elaborate.
Nine Iranian employees of the British Embassy in Tehran were detained last June in connection with opposition protests on suspicion they were abetting anti-government actions.
Eight of them were later released but the ninth suspect, political analyst Hossein Rassam, was slapped with a four year prison sentence. Mr Rassam was later released on bail pending appeal.
Iran's ties with Britain were strained even before the June 12 election in which Mahmoud Ahmadinejad was declared the winner.
Tehran condemned Britain's move in 2008 to remove an Iranian opposition group from its terrorist list, a decision later mirrored by the European Union. The group, known as People's Mujahedeen of Iran, is still regarded as a terrorist organisation by the United States.
There have also been incidents between Iran and Britain in the Persian Gulf waters.
Iran freed five British sailors a week after it detained them in December when their racing yacht drifted accidentally into Iranian Gulf waters.
In 2007, Iran seized 15 British military personnel in the Gulf, claiming they had entered Iranian waters, although Britain insisted they were in Iraqi waters. All were eventually freed.
Mr Mottaki's remarks followed a meeting on Saturday of top diplomats from Britain and five other key world powers on possible new sanctions against Iran because of its controversial nuclear programme, which the West fears masks aspirations to make an atomic bomb. The meeting apparently reached no agreement.Reuse content