An estimated 1.4million people who are 'at risk' from catching coronavirus will be sent guidance next week advising them to stop all social contact.
Health secretary Matt Hancock said those who are at an increased risk will be told to carry out social distancing measures in place from Monday.
Hancock said it was a "really big ask and really difficult" but are for "people's own protection" - adding people in those categories should “take themselves away from all social contact from Monday onwards”.
It is believed the 1.4 million people contacted will be those who are most vulnerable and with particular underlying health conditions.