This is an action, brought by the parents of children attending school in defendant school district, seeking a declaratory judgment that compulsory fees charged by the school district were unconstitutional. Plaintiffs prayed for an injunction prohibiting the school district from further assessing such fees. The trial court granted defendant’s motion for summary judgment, holding that neither the Federal Constitution, the Minnesota Consti*320tution, nor the statutes of Minnesota prohibit school districts from exacting fees for a variety of curricular and extracurricular activities.

Because there is no record for us to review, and we are satisfied that serious constitutional questions which have been raised cannot be resolved without a full trial on the merits, we remand for further proceedings in the trial court.

Plaintiffs allege that their children and others similarly situated are charged compulsory fees by the school attended by their children for such necessary materials and equipment as towels, gym shoes, workbooks, musical instruments, acrylic paints, shop materials, crayons, fabrics, and pencils. Plaintiffs assert that such charges violated Minn. Const, art. 8, §§ 1 and 2,1 as well as U. S. Const. Amend. XIV, § 1, and Minn. St. 120.06 and 123.35.

The trial court’s order was issued August 27, 1973, and plaintiffs’ appeal was taken in September 1973. In March 1974, L. 1974, c. 561, §§ 2, 3, and 4, now Minn. St. 120.72, 120.73, and 120.74, were adopted by the legislature and on April 11, 1974, were approved by the governor, to take effect July 1, 1975.2 Be*321cause the statute will render moot many of the issues raised by the plaintiffs, we decline to consider serious constitutional questions.

*322Although plaintiffs seek to bring a class action on behalf of all indigent parents, the trial court expressly held, “The court does not find any evidence that the plaintiffs are financially unable to pay the fees.” We consequently have difficulty recognizing plaintiffs’ standing to invoke the rights, of the indigent parents they purport to represent. An equally serious impediment to a consideration on the merits is the fact that neither plaintiffs nor respondent advance the claims of parents who are not indigent. If we were to pass on the rights of indigent parents only, it would leave unresolved the question of whether the parents who can afford to pay could constitutionally be required to do so.

Neither the attorney general nor the Department of Education has been given an opportunity to be heard in these proceedings, let alone introduce evidence. On remand they would seem to us to be proper, if not necessary, parties.

Nor do we have any way of determining the actual operation of the permissible policy prescribed by statute allowing school *323boards to waive the payment of fees for indigent pupils. Indeed, no party to these proceedings has shown he has been denied access to any curricular or extracurricular activity because of his refusal or inability to pay the prescribed fee.

Accordingly, we hold that the decision below was in effect rendered as an advisory opinion without a determination of what practices are actually followed under current regulations. This is a matter peculiarly within the expertise of the Department of Education, and neither this court nor the trial court can intelligently determine what fees are permissible and what are not without a full-blown hearing where school administrators, teachers, and parents have an opportunity to introduce evidence bearing on these constitutional questions. In the light of the imminent effective date of the new statutes, it would seem to us advisable that further proceedings be deferred in the trial court until new regulations and procedures have been adopted by school'administrators in response to the authority granted them by the legislature in L. 1974, c. 561. The judgment of the trial court is therefore vacated, and the matter is remanded for further proceedings consistent with the conclusions we here reach.