Johnson has said the following about Iran (on twitter, of all places...)
"Watching events in Iran with concern. Vital that citizens should have the right to demonstrate peacefully."
"We regret the loss of life that has occurred in the protests in Iran, and call on all concerned to refrain from violence and for international obligations on human rights to be observed."
Also on facebook:
"The UK is watching events in Iran closely. We believe that there should be meaningful debate about the legitimate and important issues the protesters are raising and we look to the Iranian authorities to permit this.
We also believe that, particularly as we enter the 70th anniversary year of the Universal Declaration on Human Rights, people should be able to have freedom of expression and to demonstrate peacefully within the law.
We regret the loss of life that has occurred in the protests in Iran, and call on all concerned to refrain from violence and for international obligations on human rights to be observed."
Togo's right, there has so far been nothing I'm aware of from the Labour camp (except for a somewhat confused call for solidarity against the regime " and against U.S. interference" by Owen Jones).