There is no doubt that Boris Johnson is on the back foot.

London: Folks are asking, “Did Boris Johnson lift Plan B Covid protocols because he is on the back foot politically, so he wants the public on his side? Or is his decision actually based on science?”
This reporter offers multicausal answers.
The UK is obsessed with testing, thanks to the accessibility of lateral flow tests (LFTs). People self-isolating with Covid can now end their isolation after five full days, so long as they test negative on days 5 and 6. Contacts who are fully vaccinated can also avoid isolation by testing daily with LFTs and most of those who test positive on an LFT, no longer have to confirm their result with a PCR test. UK has probably the most comprehensive testing system in the world. Everyone is entitled to as many free lateral flow packs of kits as they want, now that UK has an ample supply; since the work at home guidance is gone, many working folks are testing every day, with a commendable degree of accuracy. This is a policy that Jen Psaki, US Press Secretary, sarcastically mocked in a briefing during the second week of December 2021; public antithetical reaction to her scorn prompted a policy reversal from President Joe Biden, who agreed testing was one way to curb transmission.
The accepted science says Omicron is less transmissible and milder, plus more of the population is vaccinated thus has some degree of resistance to severe disease. The UK economy needs folks back in the office, hospital, mall, studio, theatre, pub, gym, etc. In universities, biomedical students have been worst affected, as no practical experiments have taken place. Scientists related to government projects are in agreement that mass vaccination is untenable, financially and logistically, in the long term.
Having introduced the Emergency Powers and punitive measures, the government has been looking for a valid way out of restrictions for some time and Omicron has provided it.
There is no doubt Boris Johnson is on the back foot, and relaxation of restrictions thanks to Omicron are a timely conciliation for Tory rebels and lockdown sceptics.
But the PM’s problem is deeper than that, he has disappointed the 2019 Blue/Red Wall majority intake of MPs, who were only ever tentatively onboard. The cancellation of the high speed train to the north east was a blow, the 2019 manifesto seems irrelevant, the delay in opening another CCHQ in Leeds has not helped (rumoured to be opening in 3 weeks), communication channels between the white tower of No. 10 and the MPs working at home were dismal, with MPs rebelling because they felt unimportant and one MP rebelled with his feet to join the Labour party.
Johnson’s lack of directness and escapism over “partygate” has been the last straw for disaffected Tories and their disaffected constituents. There has been a hue and cry in Parliament for his resignation. The Tory faithful have rallied around with varying degrees of sincerity, pleading with the population to wait for the now infamous Sue Gray report into parliamentary social behaviour during the 2021 lockdown. Johnson delayed his apology, mistook a lie for a fib, and has broken trust with the people.
Johnson has been the entertainer and journalistic spinner with zero accountability for too long. On 18 December 2021 this reporter said he was on his eighth life. Now it is time to be serious and a absorb the Nolan principles—the British guidance for the Seven Principles of Public Life: selflessness, integrity, objectivity, accountability, openness, honesty and leadership. This reporter will leave it to the reader to allocate a score out of seven.