Whilst I cannot find a definitive answer either to the s111 applicability to PCs or the appropriateness of setting aside EMR to pay for planning consultants - which I personally consider to be bizarre anyway - all I can do is reiterate that it doesn't 'seem' right.
Why doesn't it 'seem' right?
Because it just doesn't seem like a justifiable use of tax payers' money. The role of a PC as a statutory consultee in planning decisions is clearly defined and should be well known but I don't see how that role extends into expenditure for consultant to support / challenge to an application. Is it safe to assume that the consultant would be just as likely to be engaged by the PC to support an application that the LPA were minded to refuse as they might be to object to an application that the LPA might support? If not, why not? If yes then that would be tax payers' money being spent to provide a (potentially) unfair / inequitable advantage. It's fraught with danger either way.
What are the qualifying criteria for such action / expenditure to be invoked? Is there a % of the electorate that need to have expressed a view (one way or the other) in order for the PC to proceed and demonstrate that it is representing the will of the people? What would that % be?
I could understand if the PC were to act as a facilitator / coordinator for support / oppose community groups that had an interest in a planning application - that would readily fall in the sphere of PC influence of "...leading community engagement..."
Setting aside reserves for payment of consultants to support / oppose a planning application - nah, not buying it.
Does it 'seem' wrong? Yes. Can we define precisely why it's wrong? Perhaps no.
Generally in life, I'd normally adopt the principle that if there is no specific rule that says you can't, there is probably a way to justify that you can. Even with that starting point, a scenario still has to pass the sniff test and this one doesn't (IMHO.)
Perhaps the second/third level implications might what are the 'triggers' for using the money and who is authorised to proceed and then (if this is not appropriate) that the balance should not be in EMR but in available cash and that has implications for precept calculations and historic increases.