6. As long as national authorities remain competent to resolve credit institutions, in cases where they consider that the withdrawal of the authorisation would prejudice the adequate implementation of or actions necessary for resolution or to maintain financial stability, they shall duly notify their objection to the ECB explaining in detail the prejudice that a withdrawal would cause. In those cases, the ECB shall abstain from proceeding to the withdrawal for a period mutually agreed with the national authorities. The ECB may extend that period if it is of the opinion that sufficient progress has been made. If, however, the ECB determines in a reasoned decision that proper actions necessary to maintain financial stability have not been implemented by the national authorities, the withdrawal of the authorisations shall apply immediately.