The Foreign Office has warned Libya not to mark the first anniversary of Lockerbie bomber Abdelbaset al-Megrahi's release.
Megrahi, who is terminally ill with prostate cancer, was freed from prison on compassionate grounds by Scottish justice secretary Kenny MacAskill on August 20th 2009.
Medical advice given to Mr MacAskill indicated the only man ever convicted of Britain's worst ever terrorist atrocity had just three months left to live. But he remains alive, to the anger of the families of the 270 people who died on Pan Am flight 103 over Lockerbie in December 1988.
Tripoli gave Megrahi a hero's welcome on his return to Libya, where he is widely believed to be innocent. The Foreign Office warned Libya not to offer a similar display of support one year later.
"Any celebration of Megrahi's release would be tasteless, offensive and deeply insensitive to the victims' families," a spokesperson said.
"We have made our concerns clear to the Libyan government."
Scottish first minister Alex Salmond told the BBC he understood no such celebrations were now expected.
"It would be inappropriate because it would add to the suffering and anxiety of the relatives of the Lockerbie atrocity," he said.
Last year former prime minister Gordon Brown delayed expressing an opinion on whether Mr MacAskill was right to give Megrahi his freedom, prompting criticism from Conservative leader David Cameron and William Hague.
The pair, now prime minister and foreign secretary respectively, made clear they viewed Mr MacAskill's decision as a "mistake", the Foreign Office added.
"Particularly on this anniversary we understand the continuing anguish that Megrahi's release has caused his victims, both in the UK and the US," the spokesperson added.
"He was convicted for the worst act of terrorism in British history."
London's efforts to disassociate the British government from Megrahi's release are linked to deep anger in the US.
Many of the Lockerbie victims were American and four US senators have repeatedly demanded to meet with the Scottish justice secretary to grill him over allegations that energy firm BP sought to influence the decision to help it secure oil deals with Libya.
The Scottish government has so far refused their requests, arguing it is only accountable to the Scottish people, but Mr MacAskill has now indicated he is prepared to meet the senators.
"If US senators come across and they seek a meeting with me, I'll be more than happy to try and provide it," he was quoted as saying.
Mr Salmond added: "All we ask people to understand is every decision we've made in Scotland has followed the principles of Scots law."