Sajid Javid, UK Secretary for State for Health and Social Care stated this in his verified twitter handle.
The statement reads,
In light of the most recent data we are taking further action to slow the incursion of the Omicron variant.
From 4am Monday, only UK/Irish citizens & residents travelling from Nigeria will be allowed entry and must isolate in a managed quarantine facility.
And – from 4am Tuesday, anyone travelling to the UK from countries not on the Red List will be required to take a pre-departure test, regardless of their vaccination status.