I can't see any scenario where deciding against extending surveillance in that manner is the wrong decision for the executive: the potential downside of not doi

I can't see any scenario where deciding against extending surveillance in that manner is the wrong decision for the executive: the potential downside of not doing it is very high (in the event of an actual attack you will be hit by your opponents for endangering the public); the potential downside of doing it is only criticism from the very small number of voters who take communication privacy very seriously.