Plea of not guilty

A plea of not guilty, whether voluntarily made by the defendant or entered by order of the court, shall not be deemed to be a waiver of matters in bar or abatement or an admission of the validity of the indictment or complaint. A defendant at the time of the entry of such plea, or within ten days thereafter or within such further time as the court may order, may file such motions and other pleadings relating to matters in bar or abatement or to the validity of the indictment or complaint as he may desire without at any time retracting the plea of not guilty. Lack of jurisdiction or the failure of the indictment or complaint to charge an offense may be raised at any time during the pendency of the proceedings.