Just to look at the bigger picture for a moment...
Rather than invest in and resource the existing public health system, the govt decides to manage testing and track and trace by handing out lucrative contracts to its inexperienced private sector mates.
The govt decide that Baroness Dido Harding (wife of one of Johnson's close friends) will be heading up the pandemic response, rather than the already established and experienced PHE. This happened just before schools returned in September, meaning that they have continually advised schools to send home as few pupils as possible, often taking 48 hours to respond to a positive case, and have failed dismally at tracking and tracing contacts.
The government has, by its own admission, failed dismally to mandate enough mitigation measures to ensure that schools are as safe as possible. In fact, they have instructed schools not to use measures like mandatory mask wearing which we know lowers the risk of transmission of the virus.
In reality, it's been SLT and other school staff who have been doing the work on the ground. These public sector workers have had their pay cut in real terms over the last few years and, of course, have not been offered any financial remuneration for effectively running the public health response, including evenings and weekends.
And because SLT workers said that they do not want to work Xmas day, which they are not contracted to do, won't get paid for, and will already have worked for 6 days of their holiday, somehow they're the lazy ones that are causing all sort of childcare issues?