This was published under the 2010 to 2015 Conservative and Liberal Democrat coalition government
Mr Cameron said:
The attack on the British Embassy in Tehran today was outrageous and indefensible. The failure of the Iranian government to defend British staff and property was a disgrace.
Our immediate priority is the safety of our staff. I spoke to our Ambassador this afternoon and was reassured that everyone has been accounted for. He and his team have handled a dangerous situation with calm and professionalism.
We hold the Iranian Government responsible for its unacceptable failure to protect diplomats in line with international law. The Iranian government must immediately ensure the continued safety of our staff, return all property and secure the compound immediately. Those responsible for this criminal attack must be prosecuted.
The Iranian Government must recognise that there will be serious consequences for failing to protect our staff. We will consider what these measures should be in the coming days.