Think this data is more important than hospitalisation
Covid-related staff absences at hospitals in England have risen sharply since Omicron took hold last month, latest figures show.
The number of workers off sick for Covid reasons trebled from the beginning of December.
The Royal College of Nursing said growing absences meant the situation was "simply not safe."
NHS national medical director Professor Stephen Powis said staff were under pressure but were "stepping up".
Downing Street said Boris Johnson saw no need for further restrictions despite the staff absences, as England's current measures were "balanced and proportionate".
Earlier this week, the prime minister said he hoped England could "ride out"the Omicron wave without more restrictions.
Approximately 4% of hospital staff in England - nearly 36,000 - were off for Covid reasons each day during the week ending 2 January.
That was a rise of 41% on the previous week, and treble the 11,957 absences seen at the beginning of the Omicron wave in the week ending 5 December.
When other sickness absence is added it brings the total off to 9% - nearly double what would normally be seen at this time of year.