The UK government’s White Paper, ‘The Future Relationship Between the United Kingdom and the European Union’ set out an ambitious future relationship with the EU on data protection that builds on standard EU adequacy arrangements to provide for ongoing regulatory cooperation between the Information Commissioner’s Office (ICO) and the EU Data Protection Authorities that make up the European Data Protection Board (EDPB). The White Paper can be found here: https://www.gov.uk/government/publications/the-future-relationship-between-the-united-kingdom-and-the-european-union.
The Political Declaration sets out that the UK and the EU should make arrangements for cooperation between the ICO and the EU Data Protection Authorities.
The UK will continue to have high standards of data protection and there will be no immediate change in the UK’s data protection standards. GDPR standards (as incorporated into UK law) will still apply in the UK and the Information Commissioner will remain the UK’s independent supervisory authority on data protection.