The Labour Party received thousands of pounds from an offshoot of Scientology, it has been revealed.
The decision to accept money from a charity linked to the controversial cult was taken at the highest level by members of the National Executive Committee.
They allowed the charity, the Association for Better Living and Education (ABLE), to take a stall at the party's annual conference in Manchester.
Exhibitors at the conference have to pay up to £13,500. The stand was part of an extensive lobbying operation by Scientology members to promote its drug treatment programme, Narconon, and the criminal rehabilitation scheme Criminon.
Correspondence obtained under the Freedom of Information Act by the Evening Standard reveals how Graeme Wilson of the Church of Scientology met Baroness Scotland - then a Home Office minister - in Manchester in September.
Baroness Scotland was later invited to attend the opening of the Scientology's new base in London and was handed information about Narconon.
The invitation was passed to drugs minister Vernon Coaker who declined it to "due to diary commitments".
Critics of Narconon claim it is a front for Scientology, a "religion" founded by science fiction writer L Ron Hubbard which counts John Travolta and Tom Cruise among its devotees.
Labour allowed ABLE to exhibit despite concerns about Scientology and its offshoots.
The director of the Prison Service has said that Narconon is not a "validated programme" and has advised against its use as a treatment.
Drugs charity Addaction also opposes the programme saying it is "not scientifically sound".
Labour confirmed that the decision to accept money from the Scientologists to exhibit was taken by a committee of the NEC. NEC members include Tony Blair, GordonBrown and party chairman Hazel Blears.
A Labour Party conference spokesman said the money received was a business transaction and did not constitute a donation.
He added: "Approval for organisations looking to attend conferences is made after careful consideration by the NEC board. We do reserve the right to exclude an organisation but in this case approval was given."
He added: "We do not comment on individual exhibitors but every year exhibitors represent a range of views and opinions. Their policies may not always reflect those of the Labour Party."
In addition to the conference stand, ABLE staged a "state-of-the-art exhibition" in a hotel near the Manchester centre "for Members of Parliament and others attending the conference".
Scientology's lobbying follows revelations that followers arranged talks on drugs at schools through Narconon. A Home Office spokeswoman said it did not meet the standards required by the National Offender Management Service.
"The view is that drug treatment needs to be evidence based," she said.
• The Church of Scientology is one of the world's fastest-growing religions, claiming to have more than eight million members, with more than 100,000 in the UK. Scientology means "the study of truth". The late science-fiction author L Ron Hubbard founded thechurch in the US in 1954, based on his self-help philosophy Dianetics.