DETECTIVES are set to demand access to Downing Street and Labour Party headquarters in a bid to prove there was a potentially illegal deal at the centre of the cash-for-honours inquiry.
Metropolitan Police officers are expected to seek search warrants for both premises at the heart of Westminster in a significant acceleration of their bid to establish that honours were offered in return for huge cash donations to Labour.
Scotlan
d on Sunday understands detectives want to remove computer hard drives and paper files relating to contacts between senior Labour figures and some of their most generous benefactors.
The nine-month investigation is believed to be concentrating on an alleged "arrangement" involving some of the major witnesses in the inquiry, amounting to an agreement to give at least one of Labour's big-ticket supporters a high honour as a "reward" for a huge contribution to party coffers.
Senior sources last night said at least one benefactor could face prosecution for allegedly soliciting an honour under 80-year-old legislation.
The 1925 Honours (Prevention of Abuses) Act outlaws the offer of money or other gifts as an "inducement" in the award of a title.
The investigation is alleged to have taken a new turn following alleged inconsistencies in communications between Downing Street, party supporters - and possibly Labour HQ.
Downing Street has denied claims that detectives had uncovered a "hidden" computer network within Number 10, from which crucial e-mails appeared to have been deleted.
But the investigation team is expected to return to Downing Street in the next few days to remove computer hard drives, amid concerns that the messages in question may have been "scraped" from the network.
Scotland on Sunday revealed last month that one of Tony Blair's closest aides, Ruth Turner, his fundraiser Lord Levy, former party general secretary Matt Carter and director of government relations John McTernan were on a list of senior Labour figures facing further questioning.
Turner, 36, was arrested on suspicion of perverting the course of justice last week. McTernan was questioned under caution last week. Levy was arrested and questioned at a police station last July.
News of the new visit brought a heated response from within the Labour high command. "There should be no need for this," one senior Downing Street aide said. "Number 10 and Downing Street have co-operated fully with everything the police have asked them to do."
The response hinted at the growing tension between No 10 and Scotland Yard over the investigation.
The simmering discontent erupted into the public domain last week after a series of senior Labour politicians condemned the "theatrical" early morning swoop on Turner at her London home.
The complaints provoked a remarkable riposte from police chiefs, who warned the government was not "above the law".