(Adds SFO, lawyer and Transparency International comment, details)
By Kirstin Ridley
LONDON, May 18 (Reuters) - Britain's ruling Conservative Party on Thursday pledged to scrap the Serious Fraud Office (SFO) and roll it into a broader crime-fighting body if it wins the June 8 national election, in a move roundly criticised by lawyers and anti-corruption groups.
Prime Minister Theresa May's party manifesto document, which lists policy proposals, said it would bring the SFO under the remit of the newly established National Crime Agency (NCA), dubbed Britain's FBI, to "strengthen Britain's response to white collar crime".
The SFO has been dogged by speculation that May, a former home secretary who controlled the NCA, would revive plans to end its days as an independent investigator and prosecutor of top-level fraud and bribery after becoming prime minister last year.
The agency said only that the organisation of law enforcement was a matter for ministers. "This is a political pledge and we cannot comment," it said in an emailed statement.
But London lawyers questioned the wisdom of the move at a time when the SFO was establishing a record for itself and the NCA had yet to do so. Anti-corruption group Transparency International called it an "ill-conceived manifesto one-liner".
"Under its current director, the SFO is proving its effectiveness as a specialist economic crime enforcer," said David Corker, a partner at law firm Corker Binning. "Its work on overseas bribery and raising corporate standards in that regard is world-class.
"The NCA has not yet proved its effectiveness and there is a great danger that the fight against fraud would be compromised if the SFO's work was absorbed into its broad remit."
David McCluskey, a partner at Taylor Wessing, said complex cross-border business crime cases required specialised skills, resources and powers - and that some corporate crime was at best complicated and at worst almost impossible to prosecute.
"If these tasks are to be left to an agency which has many other priorities besides fraud, then the perception will be that this is no longer a priority for the UK," he said.
The SFO, established in 1987, has seen its budget cut and a mixed success rate in investigations such as its high-profile Libor (London interbank offered rate) prosecutions. Two bankers were unanimously and swiftly acquitted last month.
But it has also been praised by some lawmakers for clinching a handful of corporate plea deals that include a 671 million- pound ($874 million) deferred prosecution agreement with Rolls-Royce over widespread bribery in January.
Director David Green, who is due to stand down after six years in the job next April, has said there is no evidence that replacing the SFO, with its teams of investigators, accountants, prosecutors, experts and counsel, would deliver better results.
He has also argued that the SFO's priority of combating top-level fraud and bribery would become just one amongst many priorities competing for resources and attention in a larger organisation.
The NCA, which is less than four years old, has a broad remit to tackle offences ranging from organised crime to border policing, economic crime and child protection.
Jonathan Pickworth, a white collar crime partner at law firm White & Case, said it was far from certain that the NCA would be better equipped than the SFO at combating white collar crime.
"It is a gamble," he said.
$1 = 0.7677 pounds Reporting by Kirstin Ridley; editing by Ralph Boulton and Pritha Sarkar