43.—(1) The information required to determine whether a claimant has limited capability for work or for work and work-related activity is—
(a)any information relating to the descriptors specified in Schedule 6 or 7 requested by the Secretary of State in the form of a questionnaire; and
(b)any additional information that may be requested by the Secretary of State.
(2) But where the Secretary of State is satisfied that there is enough information to make the determination without the information mentioned in paragraph (1)(a), that information is not required.
(3) Where a claimant fails without a good reason to comply with a request under paragraph (1), the claimant is to be treated as not having limited capability for work or, as the case may be, for work and work-related activity.
(4) But paragraph (3) does not apply unless the claimant was sent a further request to provide the information at least 3 weeks after the date of the first request and at least 1 week has passed since the further request was sent.