How prevalent is the Omicron strain of Covid-19 that has sparked fears of more lockdowns?

The latest government figures based on PCR test results up until December 6 are now available - meaning more cases may since have been detected.

The data includes both confirmed and suspected cases of the Omicron mutation.

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About one in every six positive PCR tests are sent for genome sequencing to determine which variant they are - a process which can take many days.

A quicker way to spot potential Omicron cases is to look for a marker called the S-gene, which is missing in variants such as Omicron and Alpha but present in Delta cases.

Once identified, swabs showing so-called ‘S-gene dropout’ can then be sent for definitive testing for Omicron.

Yorkshire cases by local authority area

Barnsley - none confirmed, two suspected

Bradford - one confirmed, 10 suspected

Calderdale - none confirmed, two suspected

Craven - none confirmed, three suspected

Doncaster - none confirmed, three suspected

East Riding - one confirmed, one suspected

Hambleton - none confirmed, one suspected

Harrogate - none confirmed, five suspected

Hull - none confirmed, two suspected

Kirklees - none confirmed, three suspected

Leeds - three confirmed, six suspected

Richmondshire - none confirmed, three suspected

Rotherham - one confirmed, seven suspected

Ryedale - none confirmed, two suspected

Sheffield - three confirmed, four suspected

Wakefield - none confirmed, three suspected

York - none confirmed, one suspected

No data available for Selby or Scarborough

These are the numbers of confirmed and suspected Omicron cases in each area of Yorkshire