A client of ours has specified we are no longer able to use podiums on balcony works (over 60 of the 80 have been c ompleted in this way), whilst we appreciate a policy change and implementation they have come back with no alternatives. 

We have spoken to several suppliers who confirm the only alternative would be an ally tower, which does not change the risk, only seems to maintain the issue of competence (if not more), inspection, erection plus the access to the area is very restricted and would only fit the area in some instances not all. 

any suggestions for me as i am stumped? 

So typical of clients meddling in matters which they have no expertise...ask the client what is their preferred method. The silence may be deafening, however, if they do come back with a more expensive alternative i.e. mobile towers, then you can advise them of the extra cost - this usually puts a dampener on new ideas.

Sounds like the client has had a change of consultant or staff.  Changes after contract signature/acceptance are fully rechargeable.  No doubt somebody has read scare stories about podiums falling over balconey edge.  This is true if you have them to tall and are operating next to the handrails.  Only alternative is a full scaffold.

If I was advising the client I would however be pointing out that the risks of towers at balconey edges is well known and you should have developed a detailed risk assessment to manage the podiums in such a situation,