Mess was started by Vote Leave campaigning with no written prospectus. “Leave SM/CU” was declared late. Messy. Then ERG nutcase pressures. Then Lancaster House speech baked inflexible positions.
You’re talking about a no-deal Brexit here, which would’ve instantly shafted “our science & tech agenda”.
It would’ve frozen all UK Horizon 2020 projects with UK as coordinator (issue wasn’t technically solved), wrecked future collabs, UK reputation [thread]
Also, there would have been instant cessation of data passing between UK and Single Market labs/sci teams. That’s because there would have been no contractual underpinning for data security.
There would also have been no deal on movement of experts/ qualification recognition…
Supplies of sensitive/dangerous/ biological substances would be put on hold (eg DNA or test samples that need chilled/ deep freeze transport) for lack of known regulation and insecurity around time to transport materials that require special shipping conditions…