Speeches, etc.

Margaret Thatcher

Letter to Geoffrey Dickens MP (phone-tapping)

Document type: Speeches, interviews, etc.
Venue: No.10 Downing Street
Source: Thatcher Archive
Editorial comments:
Importance ranking: Minor
Word count: 497
Themes: Law & order, Security services & intelligence

Dear Geoffrey DickensGeoffrey,

Thank you for your letter of 9 January in which you asked whether there are any circumstances in which interception of telephones or mail on behalf of officers of the Inland Revenue or of H.M. Customs and Excise (who are responsible for VAT) can be authorised.

Interception is not used to assist the enquiries of the Inland Revenue. The authoritative statement of policy, practice and procedure in these matters is, as you suggested, the Report of the Committee of Privy Counsellors (the Birkett Report) of 1957, Cmnd. 283. That Report gives an account of earlier practice, and sets out the criteria by which the Home Secretary should decide whether this means could properly be used to assist the enquiries of, among others, H.M. Customs and Excise. The type of serious crime which the Birkett Committee thought might justify H.M. Customs and Excise seeking a warrant from the Home Secretary for interception was that of a case involving a substantial and continuing fraud which would seriously damage the revenue or the economy of the country if it went unchecked. That continues to criterion followed today. The application of that criterion means that H.M. Customs and Excise would contemplate seeking the Secretary of State's warrant in cases involving VAT only if there were reason to suspect systematic, continuing, large-scale and fraudulent evasion. [end p1]

You have also asked whether there are any circumstances in which information obtained by this means might be used as evidence. The only use to which H.M. Customs and Excise have put information obtained by these means is to assist the detection of serious cases; and it is for that purpose, and not to provide evidence for use in court, that interception is authorised.

There is one other point I should make clear. The agencies that use the product of interception for the purposes of investigation (the police, H.M. Customs and Excise and the Security Service) do not themselves authorise it (that is the Home Secretary's function) or carry it out (that is the Post Office's function). The Home Secretary's warrant is an authority to and requirement upon the Post Office to carry out an interception and to supply the product to the agency that requires it. This separation ensures two things:

(i) that the investigating agencies cannot undertake interceptions on their own account. They have to submit every case for Ministerial decision;

(ii) that the executive agency—the Post Office—will not carry out an interception that is not covered by the Home Secretary's warrant.

I must emphasise that today, no less than in 1957, the personal authority of the Secretary of State is required before any interception of postal or telephone communications may be carried out and any application for that authority receives the most careful scrutiny. It also remains true today, as noted by the Committee of Privy Counsellors, that there is no likelihood of the ordinary law-abiding citizen being affected to his detriment by this procedure.

Yours sincerely,

Margaret Thatcher.