With the official covid death toll passing 100,000 in the UK, ministers have faced questions this week about why they didn’t lockdown earlier at key points in the pandemic.

The communities secretary Robert Jenrick said on Wednesday: “I think the evidence may well show that the tiered system and the restrictions that were in place towards the end of 2020 were getting the covid as we knew it under control, but unfortunately the new variant came”.

He’s not the only one to blame the UK variant. Announcing England’s latest lockdown at the start of January, Boris Johnson told the nation: “there is no doubt that in fighting the old variant of the virus, our collective efforts were working and would have continued to work.”

But is it really true that England’s tiered restrictions would have controlled the virus if we hadn’t faced the more infectious UK variant?

The October tiers weren’t enough to stop the epidemic growing

In October, ministers resisted calls from experts on the SAGE committee to implement a short national lockdown, opting instead for the first set of tiered restrictions in England.

We now know that the new UK variant had just recently emerged, though it made up a tiny fraction of cases at that time (and wasn’t even on ministers’ radar yet). So for all intents and purposes, the October restrictions were battling the “old” virus.

And they didn’t work.

England’s chief medical officer, Chris Whitty, said on 2 November: “the early indications we have at present are that [the regional tier system] has not achieved getting the R below one”. That means the epidemic was still growing.

Indeed, the government knew by this point that they weren’t enough because it had replaced them with a national lockdown on 31 October, which lasted throughout November.

On 2 December, the government’s Winter Plan acknowledged: “the previous tiers […] mostly slowed the increase, resulting in an epidemic that kept growing”.

What about the December tiers?

December saw a second period of tiered restrictions for England. But we know they weren’t enough to contain the spread as they too were replaced with lockdown – the one we’re in now.

Mr Jenrick and the Prime Minister seem to lay the blame for this at the door of the new UK variant.

Researchers at the London School of Hygiene and Tropical Medicine and Liverpool University published their own assessment on 23 December in the Lancet medical journal.

One of the study’s authors, Dr Nicholas Davies, told FactCheck their modelling suggests that “with the tiers system in place and no new variant, there would have been a ‘third wave’ peaking around February 2021, of roughly a similar peak magnitude as that seen just prior to the November lockdown”.

It’s only one paper and it’s not a perfect comparison – the model assumes the post-lockdown tiered restrictions were the same as in October, rather than the slightly tougher December rules. But from our correspondence with Dr Davies, we understand this would not have made a significant difference to his team’s findings.

On the basis of this research, then, it seems that even without the new variant, the tiered system would not have been enough to prevent a “third wave” of the epidemic in England.

Update 29 January

After we published this article, a government spokesperson told us: “The tiering system helped to keep growth down across much of the country. However, the new variant with its much higher transmissibility required a stronger response to halt its progress.”

They said that as well as the tiered system, Mr Jenrick’s comments also included the November lockdown, which did bring cases down.

The government pointed us to data from the Office for National Statistics (ONS) that shows the “old” variant declining in areas of England where there was no new variant to compete with it (we take that to mean the North of England). They said this suggests the tier system would have controlled the previous virus. Though as Dr Davies points out, if it only works in certain parts of the country, it remains an open question as to whether the tiers can be deemed a success.

FactCheck verdict

Ministers have suggested that their strategy for controlling the epidemic in England – regional tiered restrictions in the latter part of 2020 – would have worked were it not for the new UK variant.

The October tiers were mostly battling the “old” virus – and by the government’s own admission, failed to keep it under control.

The December tiers were introduced when the UK variant had already taken off, which might cloud our ability to identify the cause of their failure.

But a study published in the Lancet suggests that even against the “old” variant, the tiered restrictions would not have been enough to prevent a third wave of the epidemic in England. By their estimates, we’d have faced a surge in cases in February about the same size as the peak that prompted ministers to introduce England’s second lockdown in November.

29 January: After we published this article, the government got in touch to say that the old variant was declining in some parts of the country where there was no new variant to compete with it. It says this suggests the tier system would have been enough to keep the epidemic under control. Though if it only worked in certain parts of the country, it remains an open question as to whether we can declare the tiered system a success. As ever, we’ll have to wait for more research.