* UK changing lockdown tiers to fight fast virus spread
* London moves to 'high' alert from 'medium' on Saturday
* Decision on stricter lockdown of Manchester put off
* Concerns grow over economic hardships under lockdowns (Updates with London going into stricter coronavirus lockdown)
By Guy Faulconbridge and Sarah Young
LONDON, Oct 15 (Reuters) - London, Europe's top financial centre with 9 million people, will enter a tighter COVID-19 lockdown from midnight on Friday as Prime Minister Boris Johnson seeks to tackle a swiftly accelerating second coronavirus wave.
The respiratory pandemic, which emerged in China last year and has killed over a million people worldwide, is spreading in most parts of the United Kingdom, whose official death toll of 43,155 is the highest in Europe.
Anger, though, is rising over the economic, social and health costs of the biggest curtailment of freedoms since wartime: one former government adviser warned some people would have trouble clothing their children soon.
Health Secretary Matt Hancock said London, as well as the adjacent, heavily populated county of Essex, would be put on "high" alert level, up from "medium", at one minute past midnight (2301 GMT Friday).
"For all who work in our great capital: I want to say thank you for what you've done to suppress the virus once, we now all need to play our part in getting the virus under control once again," Hancock said.
"I know the sacrifices this means, but I know that if we work together, we can defeat this."
London Mayor Sadiq Khan said: "I must warn Londoners: We've got a difficult winter ahead."
In the capital, whose financial district is rivalled only by New York, 11 boroughs are seeing more than 100 new cases a week per 100,000 people. The worst hit areas are Richmond, Hackney, the City of London, Ealing, Redbridge and Harrow.
'PEOPLE NOT COPING'
Manchester, in the north of England and one of Britain's largest cities, had been tipped to be moved to "very high" alert from "high", but Hancock said talks with local leaders were continuing so no decision had yet been made.
Johnson, who scored a landslide election victory in December, says his government is fighting a war against the virus and that some sacrifices are necessary to save lives.
But opponents say his Conservative government was too slow to act when the virus first struck, failed to protect the elderly in care homes, and bungled the testing system.
In areas put on the high alert level, socialising outside households or support bubbles is not allowed indoors, though work can continue and schools continue to operate.
The "very high" alert level forbids socialising, forces pubs and bars to close and prohibits travel outside the area.
The government's former homelessness adviser, Louise Casey, said the United Kingdom faces a "period of destitution" in which some families "can't put shoes on" children.
"Are we actually asking people in places like Liverpool to go out and prostitute themselves, so that they could put food on the table?" Casey told the BBC.
Liverpool in England's northwest is already in the highest-risk tier.
"There's this sense from Downing Street and from Westminster that people will make do. Well, they weren't coping before COVID," Casey added, referring to the national government's headquarters. (Reporting by Guy Faulconbridge and Sarah Young; Editing by Paul Sandle and Mark Heinrich)
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