No compensation shall be allowed to any person for services as an attorney or counsellor [counselor] to any department of the state government, or the head thereof, or to any state board or commission, except in cases specially authorized by law, but special legal assistance, may be employed by the attorney general, under his direction and control, at a reasonable compensation, in any pending action or proceeding to protect the interest of the state, with the consent and approval of the governor upon showing made by the attorney general that his department cannot for reasons stated perform such services. The costs of such special legal assistance shall be paid by the department out of which such suit or proceeding originated.