The government has released guidance on public procurement if there is no Brexit deal. The guidance addresses what will happen in relation to procurement opportunities that fall within the scope of EU procurement directives and which are currently advertised on OJEU via TED.
The guidance explains that there will be a replacement UK-specific e-notification service to replace TED. Changes to the procurement rules will also be made through amendments to existing legislation.
Here's a link to the guidance: https://www.gov.uk/government/publications/accessing-public-sector-contracts-if-theres-no-brexit-deal/accessing-public-sector-contracts-if-theres-no-brexit-deal
If the UK leaves the EU in March 2019 with no deal in place regarding future arrangements on access to OJEU/TED, a replacement UK-specific e-notification service will be made available. Changes to the procurement rules will be made via amendments to existing legislation, to ensure continued operability. All contract opportunities that would currently be published on OJEU/TED would be published on the new UK e-notification service. This would be in line with the current requirements to send notices to the EU Publications Office for publication on OJEU/TED. Publication would take place electronically and the service will be free for all users. The UK is also aiming to accede to the WTO Agreement on Government Procurement (GPA). The UK currently participates in the GPA by virtue of its EU membership.