Information is exempt information if exemption from section 1(1)(b) is required for the purpose of avoiding an infringement of the privileges of either House of Parliament.
The duty to confirm or deny does not apply if, or to the extent that, exemption from section 1(1)(a) is required for the purpose of avoiding an infringement of the privileges of either House of Parliament.
A certificate signed by the appropriate authority certifying that exemption from section 1(1)(b), or from section 1(1)(a) and (b), is, or at any time was, required for the purpose of avoiding an infringement of the privileges of either House of Parliament shall be conclusive evidence of that fact.
In subsection (3) "the appropriate authority" means—
in relation to the House of Commons, the Speaker of that House, and
in relation to the House of Lords, the Clerk of the Parliaments.