We have ours tomorrow morning in Birmingham. I know how you feel with the worries, I've just been making sure to watch the daily PM press conferences and keeping my fingers crossed that they won't shut down government buildings.
I take some comfort in knowing that usually companies which take on government contracts like Sopra Steria tend to stay open until the government says otherwise as per the terms of their contract
(I worked for one of these companies for a long time).
Keeping everything crossed for us all with future biometrics appointments