Development for which development consent is granted must be begun before the end of—
the prescribed period, or
such other period (whether longer or shorter than that prescribed) as is specified in the order granting the consent.
If the development is not begun before the end of the period applicable under subsection (1), the order granting development consent ceases to have effect at the end of that period.
Where an order granting development consent authorises the compulsory acquisition of land, steps of a prescribed description must be taken in relation to the compulsory acquisition before the end of—
the prescribed period, or
such other period (whether longer or shorter than that prescribed) as is specified in the order.
If steps of the prescribed description are not taken before the end of the period applicable under subsection (3), the authority to compulsorily acquire the land under the order ceases to have effect.