A senior medical adviser to the Government has warned that "concerning" variants of the coronavirus are set to emerge in the future.

Peter Horby, professor of emerging infectious diseases and global health at the University of Oxford and chairman of the New and Emerging Respiratory Virus Threats Advisory Group, was speaking after a mutant Covid strain was found in the UK.

He told BBC Radio 4's Today programme: "We have to be ready for future variants like this.

"This is clearly a pattern that's emerging.

"That we are going to see different viruses. Some of them will be of concern."

The warning comes as the percentage of people testing positive for Covid-19 in England has continued to increase, according to the latest infection survey from the Office for National Statistics (ONS).

An estimated 645,800 people in private households in England had Covid-19 between December 12 and 18 - the equivalent of around 1.18% of the population, or one in 85 people.

It represents a rise from 567,300 people, or one in 95, who were estimated to have Covid-19 in the period December 6 to 12.

The figures do not include people staying in hospitals, care homes or other institutional settings.