https://edition.cnn.com/2020/03/14/u...gbr/index.html
Corona can really ruin Johnson's plans. With one of the worst bed saturations amongst Western health systems and two national key advisors/officials for health being obsessed not with virological growth rates, but public behaviour control, and so having wasted an awful lot of time already, the NHS and the UK already are in an extremely disadvantageous position to deal with the pandemic overrolling the country.
And always keep on mind: most likely, very most lkikely, there will come a second wave months after the first, and possibly, very possibly, even a third.
Plans have limits if they need to be carried out in a chaotic system like our universe.