A planning authority –

(a) must prepare a draft amendment of an LPS, and certify it under section 40F , within 42 days after receiving the request under section 37(1) to which the amendment relates, if –

(i) it decides under section 38(2) to prepare a draft amendment of an LPS; or

(ii) after reconsidering, in accordance with a direction under section 40B(4)(a) , a request under section 37(1) whether to prepare a draft amendment of an LPS, it decides to prepare such an amendment; or

(b) may, of its own motion, prepare a draft amendment of an LPS; or

(c) must, if it receives under section 40C(1) a direction to do so, prepare a draft amendment of an LPS and submit it to the Commission within the period specified in the direction or a longer period allowed by the Commission.