"Stand by for start/push, short delay only due to congestion at the holding-point"
Worked a treat when I did it, I heard it at EGLL which is where I got it from, thinking 'these folks have their fingers-on-the-pulse'.
The problem now is that if you say stuff like that, chances are several members of various 'management trees', who are monitoring the GMC frequency, will be on the blower to the tower supervisor asking why XXX is being delayed.
In spite of the fact that said 'managers' have never flown an aircraft, (or controlled one), in their lives.