In the UK overall, compliance with the lockdown is high. However, in London, parks were full of joggers. One Metropolitan Police chief superintendent commented that the streets were "busier than they should have been".

Raj Kohli, borough commander of Camden, north London, said: "I still think people think it's not as serious as it is. Exercise is fine but people need to use common sense - some are using exercise as an excuse to meet friends."

There were fears, with a sunny weekend forecast at the start of what would have been the Easter holidays, that people would be tempted to leave their homes. But the Prime Minister's spokesman warned: "If we need to take further steps we won't hesitate to do so ... We can't stress enough the vital importance of the public continuing to follow the guidance and continuing to stay at home wherever possible. The consequence of not doing so is potentially more lives being lost."

The Government is scaling up its public health messaging with a series of adverts warning the public "people will die" if they don't stay home.

A Savanta poll for The Telegraph found the number of British adults in self-isolation dropped to 44 per cent on Thursday compared with 55 per cent on Monday and 46 on Tuesday per cent. Those reporting they had left the house also rose, with almost half (47 per cent) saying they had gone out on Tuesday - 10 points higher than the 37 per cent who left the house on Monday. The survey also found a drop in the approval ratings of those handling the crisis, suggesting the public was beginning to question the Government's approach.