GDPR which replaces the Data Protection Act and comes into play 25 May 2018. Brexit will not affect this even though the legislation came out of Europe and was approved by the EU parliament on 14 April 2016.
GDPR applies to data controllers (organisations that collect data from EU residents) and data processors (organisations that process data on behalf of the data controller). It also affects organisations that deal with data where the data subject (individual) is based in the EU.
Be prepared for 25 May 2018.