I would agree with CAT1,
APPLICABILITY AND USE OF THE MEL
Before Flight the MEL is intended to give guidance to the Flight Crew and Engineering of items that affect
dispatch and airworthiness of the aircraft.
The Aircraft is Considered to have been dispatched when it first moves under its own power.
After Dispatch the MEL may be referred to for information and guidance. Any action that is required should be taken in accordance with the procedures in this manual.
e.x.: Performance items that may have an adverse effect on the sector shall be reviewed before take-off
However the commander can refuse to depart even if MEL allows him to do so in accordance with JAR-OPS 1.085(d):
The commander shall:
([11])Decide whether or not to accept an aeroplane with unserviceabilities allowed by the CDL or MEL; and
