On any day on which it appears to a local authority that the vacancy condition and the local benefit condition are met in relation to qualifying high-street premises in its area, the authority may serve a notice under this section (an "initial letting notice") on the landlord of the premises.
An initial letting notice expires (if it has not been withdrawn)—
when a final letting notice in relation to the premises takes effect, or
at the end of the period of ten weeks beginning with the day on which the initial letting notice takes effect.