It's Brexit, of course it's complicated
For the most part the legal framework for public procurement and, in particular, the different procedures available to contracting authorities and entities will remain exactly the same. One key difference for contracting authorities will be the need to send notices to a new UK e-notification service instead of the EU Publications Office.
Contracting authorities have a legal obligation to publish public procurement notices. In a no deal scenario, contracting authorities may no longer have access to the EU Publications Office and the online supplement to the Official Journal of the EU (OJEU) dedicated to European public procurement (i.e. Tenders Electronic Daily (TED)). Therefore, the government has amended current legislation to instead require UK contracting authorities to publish public procurement notices to a new UK e-notification service. The new service is called Find a Tender (FTS).