In any action in which the state of Minnesota or any of its officers is a party and the amount of state expenditures for a particular purpose is challenged on the ground that the expenditure is insufficient to enable the state or any of its agencies to comply with the alleged requirements of the Constitution of the United States or of federal law, the attorney general shall petition on behalf of and provide representation for (1) an individual taxpayer, who as an authorized representative of a particular class of recipients or beneficiaries of significant state appropriations, has requested the representation or (2) any other state agency that wishes to intervene in the action. The attorney general shall oppose any attempt to require the state to expend money for any purpose in excess of the amounts appropriated for that purpose by law.