[MI6] had been seeking to authorise the agent’s activities under section 7 of the Intelligence Services Act, dubbed the “licence to kill”. It allows British agents operating abroad to break any law without fear of prosecution in the UK if they have the written permission of the foreign secretary of the day.
Six months previously the agent, likely to be an undercover informant, had been sent some “red lines” by MI6. The agent was told if they were breached, it would “result in the termination” of the informant’s relationship with the spy agency.
But when renewal of the agent’s authorisation was sought from the foreign secretary, MI6 “did not make expressly clear” that the “‘red lines’ had probably been crossed” – until the ambiguity was noted by the Investigatory Powers Commissioner