Sir Keir Starmer has denounced the killing of protesters in Iran, calling on Tehran to “exercise restraint” amid a crackdown on anti-regime demonstrations.
Weeks of unrest, initially fuelled by the nation’s struggling economy, have led to the deaths of at least 48 protestors and 2,300 detentions.
In response, Iranian authorities have also cut off internet access and international telephone communications.
In a joint statement with the leaders of France and Germany, the Prime Minister said he was “deeply concerned about reports of violence by Iranian security forces” and “strongly” condemned the killing of protesters.
The leaders added: “The Iranian authorities have the responsibility to protect their own population and must allow for the freedom of expression and peaceful assembly without fear of reprisal.
“We urge the Iranian authorities to exercise restraint, to refrain from violence, and to uphold the fundamental rights of Iran’s citizens.”
Earlier, Conservative leader Kemi Badenoch said the Iranian regime was “doing what authoritarian governments always do when they are afraid” and “trying to silence the truth” by blocking internet access.
She said: “A regime that represses its own people, crushes rights and strips away basic freedoms is the same regime that exports terror, funds extremism and threatens stability far beyond its borders. Even here in Britain, Iran is trying to murder its political opponents.
“We stand with the Iranian people who want a secular, democratic future for Iran.”
Protests in Iran began on December 28 and have transformed into the most significant challenge to the regime for several years.
Action has included chants in support of Iran’s pre-revolution leader, the shah, whose son Reza Pahlavi has called for further protests.
The demonstrations have also renewed the confrontation between Iran and the US, with President Donald Trump warning that Tehran would “pay hell” if the authorities killed protesters.
