Cheers Nick and Linker, I have actually revised it last week, in lieu of the reworded TDA version being published, it now looks like this for our next league release of ratified rules:
26 Calling for a Clock - Once a reasonable amount of time has passed and a clock is called for, a player will be given a maximum of one minute to make a decision. If action has not been taken before time expires, there will be a 10-second countdown followed by a declaration to the effect that the hand is dead. If the player has not acted before the declaration, the hand is dead. Anyone at the table, including the dealer and floor staff may call the clock. Imposed clock times should be proportionate to the structure, for example a 15 minute level should result in no longer than a 30 second clock.
Regards
Stuart