The current tier system is not enough to control the spread of coronavirus, scientists have said.

Independent Sage members said the measures are not effective enough and have varying effects in different regions.

While one member of the group, chaired by former chief scientific adviser Sir David King, said the Government was not proactive enough.

I think the tiers at the moment are clearly not enough

Dr Kit Yates, senior lecturer in the department of mathematical sciences at the University of Bath, said: “I think the tiers at the moment are clearly not enough.

“Tier 2 is not enough to do anything almost anywhere, Tier 3 is enough to bring cases down in some regions, but not in others.”

He added there are differences between different regions in terms of their population density and their demographics which change how people mix with each other.

Dr Yates said: “One rule isn’t going to be sufficient to bring cases down in every single region.

“I think there are other reasons why cases might be rising. Particularly at the moment I think the vaccine coming online has meant people perhaps relaxed a little bit, and have decided to let their guard down because they can see this light at the end of the tunnel.

“I think the Government’s messaging around Christmas, suggesting that it’s okay to meet up, has meant that a lot of people have relaxed, let their guard down early potentially.

“We see lots of people in crowded shopping streets, and this is clearly not going to help matters.

“I think at the moment that the tiers are just not tight enough, as well as having schools open as well as having outdoor mixing with people.

“But that’s not to say that they won’t be good enough, in a different situation.”

Professor Gabriel Scally, president of the epidemiology and public health section, Royal Society of Medicine, claimed the Government was a “one trick pony” and all it knows is tiers.

He added: “The Government has put all its eggs in one basket, and those eggs are breaking and the country is suffering as a result.”

While Professor Susan Michie a member of Spi-B, a sub committee of the Government’s Scientific Advisory Group for Emergencies (Sage) – and also a member if Independent Sage, said often the action taken was “too little too late”.

Speaking at the Independent Sage meeting on Friday, she said: “What the Government has done all the way along is too little too late – to be on the backfoot instead of the front foot.

“And so, and the whole tier system is waiting until things are very bad, and then slapping on a tier.

“And with a tier system, there’s a whole degree of confusion because it’s not part of a planned strategy.

“And because the Government is not thinking in advance and seeing what’s likely to happen, and acting to prevent things in the future, they’re always responding to what’s just around the corner.”

She added: “The adherence to rules has kept pretty steady since the summer, at really quite a high level, people on the whole are wanting to do the right things, but I think are really confused about what it is they’re meant to be doing.

“I don’t think the tier system as it is, is working at the moment.”

However, Professor Christina Pagel, a mathematician and professor of operational research at University College London, said that while she agreed with what the other scientists said, tiers had been working in some places.

She explained: “Something has changed in England. Under looser restrictions in the old Tier 2 London and the South East did not actually go up that much for about four weeks in October, and early November.

“So it’s not that they’ve never worked, and the North West was coming down in Tier 3, so clearly something has changed and I don’t know what it is.

“I don’t know whether it’s a combination of behaviour, news of the vaccine, temperature, Christmas shopping, knowing that Christmas is coming – all of those things mixed together.

“But there is something going on because I am actually surprised by how badly the new tiers have been given they’re stricter than the old tiers.”

A Government spokesman said: “We strengthened the measures in the tiers, following advice from Sage, and will continue to take decisive action in areas where the virus is most prevalent. We expect areas in Tier 3 to drive down R if everyone follows the rules.

“As the latest figures show, we need to remain vigilant to keep this virus under control to protect the NHS and save lives.”