Refusing legal advice on the merits criteria
It is possible for legal advice to be refused on the merits criteria. In practice it would be extremely rare that an application that would be refused on the merits criteria solely from the application for legal services form.
Occasionally law centres receive applications to defend criminal proceedings and these are clearly outside the act and can be dealt with at the application stage after consulting the managing solicitor. Outside of this, a solicitor should at least take a first consultation and obtain further details of the matter. If it becomes clear at the first consultation that legal advice should not continue because the application would not satisfy the merits criteria, then you can make an application to Legal Services at that point.
You should only make an application to Legal Services to refuse legal advice on the merits criteria prior to a first consultation after the managing solicitor considers the application.