Scanning the Cabinet Office release of papers on Lockerbie, this seems to be the killer paragraph from cabinet secretary Sir Gus O'Donnell
"24. From the point at which HMG became aware that Mr Megrahi had been diagnosed with terminal cancer, HMG judged that UK interests would be damaged if Mr Megrahi were to die in a UK jail. Policy was therefore progressively developed that HMG should do all it could, whilst respecting devolved competences, to facilitate an appeal by the Libyans to the Scottish Government for Mr Megrahi’ s transfer under the PTA or release on compassionate grounds. Such an approach was understood across all relevant Government Departments."