Video report by Health Correspondent Emily Morgan
A GP has warned healthcare workers "really, really need help" as more from the frontline fall sick.
Dr Lamis Latif has added to the calls to urgently supply frontline staff with protective equipment, telling ITV News "we're desperate".
"We've been urging for weeks. We're desperate. We're now seeing staff becoming sick, care homes and carers becoming sick so the front line is going down," she said.
She added: "We're losing doctors, nurses, health care professionals by the day because people are unfortunately becoming unwell and now because of the lack of adequate PPE we're only going to see those numbers come up.
"We're doing our best to fight this but if we're working unprotected of course we're going to get sick.
"And the frontline number will go down even more. So how are we supposed to stop this pandemic? We really, really need help."
A nurse told ITV News anonymously: "Sometimes I come on shift in the morning and there weren't any gowns, you'd have to wait an hour and a half, sometimes two hours, just for some gowns to be delivered.
"If there were seven, then obviously we had to make do, until we got more in and it made me upset, because the patients were waiting for us to go and help them."
"I do worry, my mum messages me everyday after my shift, asking if I'm ok."
Mr Sunak said the UK is not alone in experiencing shortages and said the issue is an "international challenge".
He added: "Alongside the efforts of British businesses, and our embassies around the world, we are working hard to get the PPE our frontline NHS and social care staff need."
The Chancellor said "a shipment of 140,000 gowns from Myanmar" had arrived on Monday.
The first of three expected RAF planes finally left for Turkey on Monday to collect the gowns, the Ministry of Defence confirmed.
ITV News Political Editor Robert Peston analyses the lack of PPE and its impact
said: "Absolutely everybody working incredibly hard on the front line deserves to have the equipment they need to do their jobs safely and we’re working round the clock to make sure we can deliver on that.
"We're improving our sourcing internationally and domestically to make sure we can get the PPE we need in what is a very challenging international context.
"But people on the front line can rest assured that we're doing absolutely everything we can and straining everything we can to get the equipment they need."
Public Health England head Professor Yvonne Doyle told the press conference a lack of PPE "is a concern" but insisted officials are "working very hard" to improve the situation.
She added: "Over this weekend I know, for instance, that 12 million pieces have been delivered to 141 trusts and as has been said there is incredible work going on internationally in a very high burn rate situation.
"A difficult situation undoubtedly, working very hard to make it better and trying to make sure we can deliver to where it’s most needed."
Her comments come as the Government has been criticised over the apparent lack of PPE for frontline staff.
Chris Hopson, chief executive of NHS Providers, said there was "relatively low confidence" that the shipment from Turkey would make its way into the country on Monday.
He said trusts are being forced into "hand-to-mouth" workarounds, including washing single-use gowns and restricting stocks to key areas.
Mr Hopson said trusts were reserving the stock of fluid-resistant gowns they do have for areas of high clinical risk, such as intensive care units, and using workarounds in other areas.
"There’s one trust that’s basically discovered that if you launder those gowns at 60 degrees [...] there’s probably up to three times that you can do that, and the gowns appear to still be fully fluid-repellent," he said.
Mr Hopson said such as move is not "ideal" and is "really hand-to-mouth".
While there had been many problems with consignments from abroad failing and the wrong items being sent, Mr Hopson said: "I suppose the question that we will need to ask whether this is over, is actually: was the pandemic stock reserve that was meant to tide us over, was it correctly configured?"
On Monday afternoon, Downing Street said the Royal Air Force was on stand-by to bring the delayed shipment of medical gowns from Turkey to the UK.
"We are working to ensure that that shipment is delivered as soon as possible. The RAF is on stand-by to take off as soon as the shipment is ready.
"But, to be clear, we are not reliant solely on Turkey for the delivery of gowns and plenty more orders are lined up and expected."
The NHS Confederation - which represents organisations across healthcare - has also reacted angrily to government promises of more PPE.
Its chief executive, Niall Dickson, said delays on the shipment from Turkey "makes a difficult situation worse," adding:
"It would have been better had the Government not made the announcement in the first place" and said staff would need to make their own assessment over whether they felt safe with the PPE currently on offer.
Mr Dickson told BBC Radio 4's Today programme that it was wrong to focus on individual consignments of PPE because "bitter experience over the last few weeks" has shown they cannot be relied upon, with some boxes containing the wrong items and thousands of pieces missing.
"So rather than being marched up to the top of the hill and being marched back down again, let’s just focus on what we know we can be certain of," he said.
The NHS is thought to use around 150,000 gowns a day, meaning the stock from Turkey would last less than three days.
Culture Secretary Oliver Dowden said he was hopeful the gowns would still arrive, telling BBC One's Breakfast programme: "We are very hopeful that later today that flight will take off and we will get those gowns.
"We are working very hard to resolve this, there have been challenges at the Turkish end.
Another 25 million gowns from China had been procured and the UK would be "getting those shortly as well", Mr Dowden said.
The Culture Secretary told ITV News "we are not alone in this" and added "all other countries are facing this kind of challenge".
Dr Chaand Nagpaul, chairman of the British Medical Association, said: “We made it clear weeks ago that we need to do something about the likelihood of a lack of protective equipment.”
Claudia Paoloni, president of the doctors’ union HCSA, said: said: “Our NHS workers are going above and beyond on a daily basis to heal.
"They should expect at the very least adequate protection to keep them fit and well to engage in this fight.
“Yet instead they are being asked to sacrifice themselves due to the failings of others.”
Lack of PPE equipment for frontline staff is 'deeply worrying' says Shadow Chief Secretary:
Shadow Chief Secretary to the Treasury Bridget Phillipson said it is a "deeply worrying" situation.
She said: "It's deeply worrying that still too many of our frontline workers in the NHS and in social care are telling us that they don't have access to the right kind of protective equipment."
"They shouldn't have to put themselves in harms way to look after the public," she added.
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