(31)Effective recovery and resolution of insurance and reinsurance undertakings or group entities operating across the Union requires cooperation among supervisory authorities and resolution authorities within colleges of supervisors and resolution colleges at all stages of the process, from the preparation of pre-emptive recovery and resolution plans to the actual resolution of an undertaking. Where authorities disagree on decisions to be taken with regard to groups and undertakings, EIOPA should, as a last resort, play a mediation role.