Railways - Procurement regulation for train operators post Brexit

Procurement in the Great British railways industry has for many years been governed by laws, procedures and regulations that have their origins in European Union (EU) law. For the railways industry, this has primarily manifested in the Utilities Contracts Regulations 2016 –which is becoming more frequently used "in-life" (UCR) and Regulation 1370/2007 – which is used for franchise procurement (Regulation 1370). So now that the UK is no longer in the EU, what is the current position and what happens next?