Before the end of the period to which an environmental improvement plan (the “old plan”) relates, the Secretary of State must prepare a new environmental improvement plan (the “new plan”) for a new period in accordance with this section, section 14 and section 15.

The new period must begin no later than immediately after the end of the period to which the old plan relates.

At or before the end of the period to which the old plan relates the Secretary of State must lay before Parliament, and publish, the new plan.