Flavour Physics in HL-LHC

The LHCb physics programme is currently anticipated to run until 2030 (LHC long shutdown 4), utilising the LHCb Phase-I Upgrade detector which is currently in construction. The operation of the LHC is now approved in its high luminosity phase (HL-LHC) to run until at least 2035. Over the last year we have been exploring the possibilities for consolidation of the experiment and a high luminosity LHCb detector, a Phase-II upgrade, to operate in the 2030s. We have recently submitted an expression of interest for this experiment to CERN.  The physics prospects and experimental challenges of this project will be discussed.