A senior MI5 official also conducted what is believed to be the first briefing for journalists, but cautioned against raised expectations. 'This is a significant step for us . . . but it doesn't necessarily mean we will take any further particular steps. Don't see this as the beginning of a great avalanche of openness.'
The 36-page booklet, which costs pounds 4.95 from government bookshops, reveals much about the service, including its motto - Regnum Defende ('Defend the Realm') - its badge and an internal breakdown of departments, but says little about its operational activities.
A pie-chart shows that about 70 per cent of its work is against terrorism - of which most is Irish - and only 5 per cent against subversion. Since October, the service has had the lead role in gathering intelligence on the IRA in Britain.
The remaining 25 per cent of work involves counter-espionage and work to prevent proliferation of chemical and nuclear weapons. The source said that before 1991 counter- espionage would have been double the size it is now.
The service employs about 2,000 people, more than half of whom are women; the same proportion are under forty. Its core work is carried out by its 340-strong General Intelligence group, in effect an officer class, mainly recruited directly from universities; 42 per cent are women. 'We are an equal opportunities organisation - there is no job that a woman cannot do,' the source said.
The source said the service wanted to dispel the myth of a 'bowler-hatted brigade with rolled umbrellas, staffed entirely by ex- Army officers' and added: 'We are a go-ahead organisation.' It was also disclosed that some of its recruitment is done anonymously through commercial agencies, where those with experience in the 'management of information' might be sought.
In the signed introduction to the brochure, Mrs Rimington says it is designed to dispel some of the more 'fanciful allegations' surrounding MI5's work but stresses there is a 'clear limit' to what can be made public without endangering staff or undermining its effectiveness.
She says the end of the Cold War has led to rapid changes in the service, with a greater emphasis on preventing the spread of nuclear and chemical weapons. She denies that the service wants to become involved in the investigation of organised crime or drugs.
The introduction also says: 'Neither is it part of the service's function in protecting national security to carry out any form of monitoring of individuals on the grounds that they are well known in public life or hold positions of particular responsibility.' The source specifically denied that the service had taped the Royal Family's telephone calls.
Mrs Rimington says that for the first time 'with the move towards greater openness' it is possible for members of the public who believe they have useful information to contact MI5 directly. The booklet gives an address: PO Box 3255, London, SWIP 1AE, but the source stressed that the service was still unable to welcome personal callers or issue a telephone number. The source said a box number for MI5 - 'Box 500' is often used among police and Whitehall officials as an informal code for reference to the service - was still in existence but declined to give further details.
The booklet does not give MI5's current addresses in London. Its headquarters are known to be in buildings in Gower Street near Euston Station, where Mrs Rimington yesterday became the first head of the service to pose for photographers. The booklet says that in 1994 it will be moving to new premises at Millbank, near the Houses of Parliament.
Neither the booklet or the source disclosed any details about the funding of the service, which the Government has consistently refused to publish. But the source said the number of employees had increased slightly in recent years, involving increased expenditure.
The service, founded in 1909, was put on an official footing only four years ago under the 1989 Security Service Act. The source stressed accountability through the Security Service and Interceptions of Communications Commissioners.
Although the Government has rejected suggestions that MI5's work should be scrutinised by MPs - members of the Home Affairs Committee were allowed only a well- publicised lunch with Mrs Rimington at Gower Street - it is believed to be considering allowing a committee of Privy Councillors a degree of oversight of both MI5 and MI6. The latter, the Secret Intelligence Service, deals with overseas intelligence gathering; its existence was acknowledged only last year and it has yet to publish a booklet on its activities.
Tony Blair, the Shadow Home Secretary, said: 'I welcome this move, but greater openness must now be accompanied by greater accountability'.
The badge of the Security Service, designed by Arundel Herald of Arms. The winged sea-lion refers to MI5's associations with the three armed services. The portcullis, badge of Parliament, symbolises the service's duty to uphold parliamentary democracy. The Latin motto - 'Defend the Realm' - is taken from the directive issued to the service in 1952 by Sir David Maxwell Fyfe, the Home Secretary
Security veil lifted, page 2