I'd like to see doctors and nurses demand that our border is closed. Better to do it now and not gingerly do a wait and see how things go situation.
We can't rely on people doing the right thing and isolating after coming into our country.
Check out the video here* i.e. press conference by WHO - from memory the key message is test and trace (trace contacts). The Chinese, and South Korean, Government's were able to massively increase testing i.e. to reduce the transmission of the virus. I'm not sure what the issues are for the UK Government following the mass testing route - lack of PCR test kits/personnel --- both? Anyone know? Is Porton Down capable of producing testing kits on the scale needed?
*
https://www.weforum.org/agenda/2020/03/world-health-organization-latest-coronavirus-covid19-news/