TEHRAN (Reuters) - Iranian hardliners pressed on Thursday for legal action against moderate leaders accused of inciting post-election turmoil that has dimmed Western hopes of engaging Tehran on its disputed nuclear programme. Those who hold illegal rallies and gatherings should be legally pursued, parliament member Mohammad Taghi Rahbar was quoted as saying by the Javan newspaper. It said he was among several lawmakers preparing to write to the judiciary complaining about defeated candidate Mirhossein Mousavis activities after the disputed June 12 election. The student branch of the pro-government Basij force, which helped police suppress street protests after the vote, has also urged the attorney-general to take Mousavi to court. The authorities have blamed Mousavi for last months violence, in which at least 20 people were killed. Mousavi, who says the poll was rigged in favour of President Mahmoud Ahmadinejad, rejects the charge. The unrest has posed a dilemma for Western powers torn between sympathy for the protesters and a desire to keep alive chances for dialogue on what they suspect is an Iranian nuclear weapons programme. Iran denies it is seeking to make bombs. In Berlin, German Chancellor Angela Merkel said she wanted next weeks Group of Eight summit to send a strong signal to Iran, without forfeiting possible talks on the nuclear issue. I hope the meeting sends a strong message of unity, a united message that the right to demonstrate and human rights cannot be separated and that they apply to Iran, Merkel said. I strongly support President (Barack) Obamas offer to Iran of direct talks. We will accompany this in a united way. We cannot drop the issue of a nuclear-armed Iran just because of the current situation. That would be completely wrong. The leadership in Iran must know that if they choose a path of reason, then we want Iran to develop prosperously, Merkel told the Bundestag lower house of parliament. But if this is not the case, we will not shy away from stating our opinions and showing solidarity with those, including members of the British embassy, that have been put under pressure. Germany is one of six world powers which have offered Iran economic and other incentives if it stops enriching uranium, a process that can produce fuel for power stations, or if carried further, for nuclear weapons. Iran has refused to halt the work. The semi-official Fars news agency said seven people linked to anti-revolutionary groups had been detained for taking part in riots and unrest in Tehran and the northwestern city of Qazvin.