Arraignment shall be conducted in open court. It shall consist of reading to the accused the charge on which he will be tried and calling on him to plead thereto. In a felony case, arraignment is not necessary when waived by the accused. In a misdemeanor case, arraignment is not necessary when waived by the accused or his counsel, or when the accused fails to appear. An accused may plead not guilty, guilty or nolo contendere. The court may refuse to accept a plea of guilty to any lesser offense included in the charge upon which the accused is arraigned; but, in misdemeanor and felony cases the court shall not refuse to accept a plea of nolo contendere. With the approval of the court and the consent of the Commonwealth, a defendant may enter a conditional plea of guilty in a misdemeanor or felony case in circuit court, reserving the right, on appeal from the judgment, to a review of the adverse determination of any specified pretrial motion. If the defendant prevails on appeal, he shall be allowed to withdraw his plea. Upon rejecting a plea agreement in any criminal matter, a judge shall immediately recuse himself from any further proceedings on the same matter unless the parties agree otherwise.