Four people have now died having contracted the Indian variant of concern as of May 12, according to data published by Public Health England (PHE).
It comes as new coronavirus cases involving the variant - strain B16172 - have more than doubled in a week, going from 520 last week to 1,313.
The cases are spread across the country, with the majority in the north west - mainly in Bolton, Sefton in Merseyside, Blackburn in Lancashire and London.
Health Secretary Matt Hancock said the situation was being monitored carefully and the government 'will not hesitate to take further action if necessary'.
Mobile testing units have been deployed in Bolton and door-to-door PCR Covid-19 testing has been offered to 22,000 residents.
A vaccine bus has been set up to increase uptake among those who are eligible and a rapid response team of 100 nurses, public health advisers and environmental health officers has been sent in.
Surge testing has also been deployed in Sefton, after cases of the Indian variant were confirmed in the Formby area, as well as in parts of London, including Hillingdon, Hounslow, Redbridge, Tower Hamlets and the Royal Borough of Kensington and Chelsea.
Greater Manchester mayor Andy Burnham has called for vaccination to be rolled out among younger generations in areas of concern, while both the mayor and Blackburn with Darwen council's director of public health, Professor Dominic Harrison, have strongly opposed a potential reintroduction of local lockdowns.
