More than one in five deaths recorded in England and Wales are now linked to coronavirus, new figures show.

Data from the Office for National Statistics (ONS) shows Covid-19 was mentioned on 3,475 death certificates in the week ending April 3, including hospital, care home and community deaths.

This means coronavirus has pushed the death toll in England and Wales to its highest level since official weekly figures began in 2005.

And the Department of Health said 12,107 patients have died in hospital after testing positive for the virus in the UK as of 5pm on Monday, up 778 from the previous day’s total, while confirmed cases reached 93,873.

As those figures were published, it emerged that impact of lockdown could see the UK economy plunge 35% between April and July with unemployment expected to hit 3.4 million – around one in 10 of the working population – if the lockdown lasts three months, followed by a partial lifting for three months.

Experts at the independent Office for Budget Responsibility (OBR) added that, on its new prediction, GDP will then jump 25% in the third quarter and a further 20% in the final three months of 2020.

The ONS figures showed that, in the week to April 3, some 16,387 people died in England and Wales, an increase of 5,246 deaths compared with the previous week and 6,082 more than the five-year average.

But care home providers have warned they are seeing a higher number of cases and deaths than are officially reported, in part due to a time lag with the ONS figures.

MHA, a charitable operator, said there had now been 210 deaths across 131 of its homes, with outbreaks in about half of its homes.

And around two thirds of care homes run by Britain’s largest care home operator HC-One have seen cases of Covid-19.

Sir David Behan, former chief executive of the Care Quality Commission (CQC) and now executive chairman of HC-One, said 232 care homes run by the firm have confirmed or suspected cases of Covid-19.

He said the figures are a “more realistic picture” of what is going on in care homes across the UK than official figures suggest.

Sir David told BBC Radio 4’s Today programme HC-One homes currently had 2,447 cases and had seen 311 deaths. Around one in three of deaths in its care homes are linked to Covid-19, he said.

It comes after the Department of Health and Social Care told the PA news agency on Tuesday lunchtime that there had been coronavirus outbreaks at 2,162 care homes in England.

Professor Martin Green, chief executive of Care England, which represents private care home providers, said “thousands of people” have shown symptoms and thousands had died in England’s care homes.

The ONS figures show that around one in 10 of all deaths involving Covid-19 now occur outside hospitals.

From 406 such deaths recorded since January, 217 took place in care homes, 33 in hospices and 136 in people’s own homes.

Professor Tom Dening, from the University of Nottingham, said the overall ONS data also showed a sharp increase in deaths in the community that are not known to be due to Covid-19.

He said many of these could in fact be due to Covid-19 that was not diagnosed, while others could be due to people not seeking help when ill, existing conditions getting worse or people drinking and smoking more, leading to accidents.

On Monday evening, Channel 4 News reported that a whistleblower working on death registrations in the south of England said care deaths were not being properly recorded, with some GPs opting to list conditions such as dementia on death certificates instead.

Niall Dickson, chief executive of the NHS Confederation, which represents organisations across the healthcare sector, said figures on care homes must be released daily.

“The spread in care homes has largely gone under the radar because the figures are not released in the same way as the daily statistics for deaths in hospitals,” he said.

“It cannot be said often enough the NHS and social care are interdependent. What happens in one sector, affects the other. We understand why so much effort has been directed to create capacity in hospitals and the response to that call from the NHS has exceeded all expectations but ambulances, social care, GP and community services have not been given the priority they deserve and we need to put that right urgently.”

Shadow social care minister Liz Kendall also said ministers must now “publish daily figures of deaths in care homes so we know the true scale of the problem and how fast it is spreading”.

But Work and Pensions Secretary Therese Coffey said on Tuesday she thinks the current system is fair.

She told the Today programme: “I think that the certification by doctors is happening regularly, that is being collated by the ONS and it is being published weekly by the ONS.

“I think that is a fair system of getting that picture, that unfortunate picture, across the country of where deaths are happening due to coronavirus, and I think that is a trustworthy way to go about this by the medical certificates signed off by doctors.”

Ms Coffey also said “people will need to wait” to find out when lockdown measures across the UK will be lifted as more data on how the measures are working is gathered.

She added: “There are legislative elements which will need to be sorted out at the appropriate time, but we will continue to review the evidence.

“I’m conscious that people would like to know sooner but it would be irresponsible of the Government to just issue messages now without having been through that assessment and the recommendations and careful consideration of it.

“So people will have to just wait a little bit longer and more will be said at the end of this week.”

The Scientific Advisory Group for Emergencies (Sage), which advises ministers, is due to hold its regular meeting on Tuesday to discuss the Covid-19 pandemic.

Meanwhile, the Health Service Journal (HSJ) reported that London’s Nightingale hospital treated 19 patients over the Easter weekend as other hospitals managed to stay within capacity.