Human rights lawyers are to sue Foreign Secretary William Hague over the alleged use of intelligence in assisting US drone attacks in Pakistan.
The case is being raised at the High Court in London on behalf of Noor Khan, whose father was killed in a US strike.
Lawyers say civilian intelligence officers who give information to the US may be liable as "secondary parties to murder".
Attacks by pilotless US aircraft have become a key weapon in the US's fight against terrorism in Pakistan.
But many Pakistanis see them as a breach of their sovereignty and the cause of frequent civilian deaths.