Whilst I agree with RAC's initial response, this raises issues about roles and responsibilities. If the councillor is paying the bill, who is the solicitor's client? Somebody must sign a client agreement and it is generally accepted that it will be the person paying for the service. The councillor paying for the service could claim ownership of the legal advice and opt not to share it with his or her fellow councillors in its unedited entirety, particularly if they have a vested interest in the outcome of the legal advice.
If the council has resolved to seek legal advice, the council should receive the advice, act appropriately thereon, pay the bill and claim the VAT back.
Finally, legal advice is usually free as part of a parish council's insurance package, so that would have been my first recommendation.