The new, more infectious strain of Covid-19 is "spreading like wildfire" through Cumbria, the county's public health director has said.

Colin Cox, Cumbria's public health director, said that the new variant of Covid-19 is responsible for "more than 75 per cent" of Covid-19 cases "in much of the county".

It is the rapidly rising rates of infection throughout the majority of Cumbria, coupled with the resulting pressure Covid-19 infections were now placing on local hospital services, that led the Government to impose the toughest Tier four restrictions on the county.

Infection rates are highest in the Eden and the Carlisle districts, where they are currently more than 500 cases per 100,000 people per week and more than 400 cases per 100,000 respectively.

Mr Cox said that the patterns associated with the spread of cases in Eden is "very different to anything seen before".

He said the district has been experiencing a number of outbreaks in which a "very large proportion" of the people who could be affected end up testing positive for Covid-19.

"50 per cent of a workplace, for example, might end up being off with Covid," Mr Cox said.

He added that a number of outbreaks had arisen recently in workplaces, schools and care homes across the Eden district, which had been driving the rise in cases.

The possibility therefore that the return of schoolchildren to the classroom in January may contribute towards a further rise in cases is a "concern" for Mr Cox.

"We've seen in Eden in particular that a lot of the transmission we were seeing was associated with schools," he said.

Mr Cox added that it "can't be ruled out" that the recent rise in Covid-19 cases has been driven by individuals travelling into Cumbria from outside of the county.

However, he said that there was "no evidence" for this.

"Most of the evidence we've seen about transmission has been associated with schools and workplace outbreaks," he said.

He added that any rise in cases tied to the mixing of households at Christmas would only begin to be detectable now, as "it takes several days for that transmission to happen".

On the prospect of further measures that might be taken to control Covid-19, Mr Cox said he believed a further national lockdown to be "likely" at some point "in the not too distant future.

"In terms of controlling the virus, that's what worked the first time," he said.

"It had started to work the second time. The tiering arrangements have not been so successful in containing the virus."