British prime minister Boris Johnson has urged people not to travel to or from two "hotspots" where the Indian variant of COVID-19 is rampant.
Bolton, near Manchester, and nearby Blackburn, have seen a big uptick in Indian variant cases.
Last week Bolton recorded 451 overall cases per 100,000 people, the highest in England.
Downing Street has also urged people in Leicester, Burnley, Kirklees, Bedford, North Tyneside and the London Borough of Hounslow to avoid meeting indoors but it has transpired that the advice was only published online, on Friday 21 May.
The leader of the opposition Labour Party, Sir Keir Starmer, tweeted: "Making a major change that will impact so many people without even telling them is utterly shameful."
He said the government needed to “provide clarity” quickly and added: “Local lockdowns are the wrong approach for both public health and local economies.”
Meanwhile Austria is banning British tourists because of the fear they will bring the Indian variant.
Britain has been added to Austria's list of "virus variant states," which includes India, Brazil and South Africa.
Scientists do not if the Indian variant is more resistant to vaccines but it is believed to be easier to transmit.
Dr Jeremy Kamil, a virologist at Louisiana State University, told the BBC: "I doubt whether the Indian variant is more infectious than the UK variant - and we must not panic.”
Around two-thirds of people in Britain have received at least one dose of a COVID-19 vaccine.