Government scientific advisers believe the rate of coronavirus transmission – the R – has not breached one across the UK, despite concerns about the North West and South West, Health Secretary Matt Hancock has said.

In a suggestion that regional lockdowns are looking increasingly likely, Mr Hancock said the North West in particular represented a “challenge” that needed to be addressed.

It comes as he announced that all hospital visitors and outpatients in England will be required to wear face coverings from June 15, while all hospital staff will need to wear surgical masks.

Mr Hancock told the daily Downing Street briefing that new figures on the R confirm “there is a challenge in the North West of England to address and, to a lesser degree, in the South West of England.”

He said the Scientific Advisory Group on Emergencies (Sage) believes the R is below one across the UK but the Government wants to “increasingly have an approach in tackling local lockdowns where we spot a flare-up.”

Earlier, Sage acknowledged there might be some places in England where the R – which is the number of people an infected person passes the virus onto – is close to one, which if exceeded could see the virus spread exponentially.

But the Government’s value remained between 0.7 and 0.9 for the UK as a whole, though the figure has a two to three week lag, meaning it does not account for the latest easing of the lockdown.

A separate report from Public Health England and Cambridge University, which estimates what the value is currently, put the North West on 1.01 and the South West on 1.00.

The figure was lowest in the Midlands at 0.9 and stood at 0.95 in London.

PHE medical director Dr Yvonne Doyle said: “Our estimates show that the regional R numbers have increased although they remain below one for most of England – this is to be expected as we gradually move out of lockdown.

“It is vital that everyone continues with social distancing, practising good hand hygiene and must remain at home and order a test if they have symptoms.”

PHE estimated there are 17,000 new infections each day in England, with a range being at between 11,000 and 25,000.

But Office for National Statistics data put the new cases at 5,600 daily, down from around 8,000 a week ago.

The PHE research warned that there is some evidence the value has risen in all regions, saying it was probably due to increasing mobility and mixing between households and in public and work settings.

Announcing the new face covering policy for hospitals, Mr Hancock said the Government wanted to ensure that “even as the virus comes under control” hospitals are a place of “care and of safety”.

He said: “As the NHS reopens right across the country, it’s critically important to stop the spread amongst staff, patients and visitors too.

“One of the things that we’ve learnt is that those in hospital, those who are working in hospital, are more likely to catch coronavirus whether they work in a clinical setting or not.

“And so to offer even greater protection we’re also providing new guidance for NHS staff in England which will come into force again on June 15 and all hospital staff will be required to wear type one or two surgical masks.

“And this will cover all staff working in hospital, it will apply at all times – not just when they are doing life-saving work on the frontline – and it will apply in all areas, except those areas designated as Covid-secure workplaces.”

Mr Hancock said that while health workers are more likely to be diagnosed with coronavirus, the R in health and social care does not appear to be higher than in the community.

“In terms of the R rate, of course there is a higher incidence of new cases amongst health staff and social care staff – that has shown up in all of the studies,” he said.

“But that is not rising as a proportion and that implies that there isn’t a different R, so to speak, in health and social care.”

Earlier, Transport Secretary Grant Shapps said face covering should not be mandatory for shoppers, despite them becoming compulsory on public transport in England from June 15.

In other developments:

– British Airways’ parent company was considering taking legal action against the Government’s decision to impose a 14-day quarantine on international arrivals.

– The Equality and Human Rights Commission announced an official inquiry into the racial inequalities “laid bare” by the pandemic.

– Analysis by the PA news agency indicated that black, Asian and minority ethnic (Bame) staff accounted for 60% of frontline health workers whose deaths have been linked to Covid-19.

– The idea of using a call centre-based system to trace contacts of people infected by Covid-19 was suggested in February, new documents presented to Sage reveal.

– Another document from February given to Sage suggested that discharging people to care homes from hospital would risk transmission of coronavirus.

One crucial means of suppressing transmission of Covid-19 is the NHS test and trace system, which seeks to track people down who have come into contact with an infected individual and tell them to isolate.

Downing Street was forced to defend the system after the Guardian reported that the scheme’s chief operating officer, Tony Prestedge, told staff it would not be at full speed until September at the earliest.

Ministers have been unable to say how many people have been traced under the system, but the Prime Minister’s official spokesman said: “Thousands of people who have tested positive have been contacted in a matter of days and their close contacts successfully traced, using both online services and over the phone.”