Police officers have accused the Government of being willing "to sell its soul for trade deals" following the disclosure that Jack Straw agreed that the killer of Pc Yvonne Fletcher would not be brought to justice in Britain.
In a letter to Gordon Brown, Paul McKeever, the chairman of the Police Federation, said he was ''shocked, appalled and disgusted'' that the UK agreed the murderer would go on trial in Libya.
The Foreign Office has conceded that any trial for the shooting - which took place outside the Libyan embassy in London 25 years ago - will take place in Tripoli.
The agreement was reportedly struck three years ago, when trade deals worth hundreds of millions of pounds were being negotiated.
Mr McKeever wrote: ''Together with the 140,000 police officers throughout England and Wales that the Police Federation represents, I was shocked, appalled and disgusted" at the news of the agreement.
''This is an absolute disgrace. Pc Fletcher was gunned down in cold blood 25 years ago by a cowardly and callous killer who managed to flee to Libya.
''Now we discover your government rolled over three years ago, abandoning any attempt to bring Yvonne's killer to face the UK courts and justice.
''Only you and your colleagues know the true reasons why such an arrangement was agreed but for those I represent and for a large number of the public the timing of the agreement would suggest your government was prepared to sell its soul for trade deals being negotiated at the time.''
Pc Fletcher was gunned down as she patrolled a demonstration by Libyan dissidents in central London on April 17 1984. The shots were fired from the first floor of the embassy building.
Despite repeated visits to Tripoli by Metropolitan Police officers her killer has never been brought to justice.
The Foreign Office said it was ''entirely misleading and simply wrong'' to suggest there was a secret deal.
''Libyan law did not allow for the extradition for trial in other countries so a trial in Libya was the only outcome that would reflect our determination to see justice done,'' a spokeswoman said.
