Speculation over a fourth, stricter tier of coronavirus restrictions is continuing after the foreign secretary refused to rule the idea out.

Asked about reports, Dominic Raab told BBC Radio 4’s Today programme: “We’re always ready for further measures that we can take. But I think the most important thing about further measures is that we continue on the track we’re on targeting the virus.”

And he said the public would find it “desperately unfair” if a national lockdown was imposed given that infection rates vary so widely across the country.

He told BBC Breakfast: “I think intuitively as well as scientifically if you look at what we’re trying to achieve, [that] is to focus on where the virus is the strongest or where the uptick is the greatest.

“Also I think in areas where the virus is not picking up, I think people would feel it was not only counterproductive or ineffective but desperately unfair for measures to be imposed across the board.”

It comes in the same week that health secretary Matt Hancock also refused to rule out the possibility of a new tier of restrictions. 

There have been reports that Whitehall is in discussion with local authorities about imposing a further layer of coronavirus restrictions – “tier 3 plus”, or tier 4. 

According to the i newspaper, Whitehall sources expect to make the decision if the existing three-tier system has not made an impact by mid-November.

Tier 3 measures include the closure of pubs and bars that don’t serve food, gyms, soft play areas and casinos. A fourth tier could see the closure of restaurants and non-essential retail, the newspaper said.

On Monday, Hancock told BBC Breakfast the government would “rule nothing out” at the prospect of the new restrictions.

Tier 1: medium

Nationwide restrictions, including:

Only meet other people in groups of six or less (“rule of six”)

10pm curfew for hospitality

Tier 2: high

As Tier 1, plus:

No households allowed to mix indoors. “Rule of six” applies outdoors including private gardens

Tier 3: very high

As Tier 1 plus: 

No households allowed to mix indoors or outdoors

All pubs and bars to close unless they can operate as a restaurant

People advised against travel in and out of areas