In recent months, the arbitrary detention of students and the targeting of government critics have increased. Scholars and students who criticize the ruling clerical establishment have faced death sentences, teaching bans or long prison terms. Several government officials and close associates of reformist President Mohammad Khatami have been held incommunicado for months because they published a poll showing that a majority of Iranians favor restoring relations with the United States. "Despite years of rhetoric about reform, recent developments in Iran are not at all positive," said Hanny Megally, executive director of the Middle East and North Africa division of Human Rights Watch. "The British government should press Iran to make real and substantive progress on human rights."

Human Rights Watch urged the British Foreign Secretary to impress upon Mr. Kharrazi that the performance of the Iranian government as a whole will be judged according to its compliance with international human rights norms.

"The judiciary plays an overtly political role in targeting for prosecution leading reformist personalities, and in ordering the closure of scores of independent newspapers and magazines," said the letter, signed by Mr. Megally and Human Rights Watch London Director Steve Crawshaw.

Iran is caught in a continuing power struggle between elected reformers, who control both the presidency and parliament, and clerical conservatives, who exercise authority through various offices including Supreme Leader Ayatollah Ali Khamenei, the judiciary and the Council of Guardians, and elements of the security forces.