Jack Straw, the former Foreign Secretary, will have his legal bills paid by the taxpayer in any court case over the "rendition" of terror suspects.
A Libyan military commander wants to sue Mr Straw over suspected British involvement in the chain of events that led to him being tortured by Muammar Gaddafi's regime. Abdelhakim Belhaj's lawyers claim Mr Straw signed papers that facilitated his rendition, at the same time that the government was officially denying it deported suspects to countries where they faced possible torture.
The legal action is against Mr Straw personally, but senior civil servants have indicated privately that if he needs legal representation to answer the charge, the taxpayer will pay.
A spokesman for the Cabinet Office said it did not comment on potential legal claims but added: "The Government provides appropriate representation to HM Government and ex-HM Government employees, ministers or officials, in relation to potential civil liability that arises in the performance of their official duties."
Mr Belhaj and his wife allege that CIA agents took them from Thailand to Libya, via Diego Garcia, an Indian Ocean territory under British jurisdiction.