Former Labour party leader Jeremy Corbyn said he was "astonished" by the state of the Queen Elizabeth Hospital in King's Lynn at a rally attended by more than 200 people.
People gathered in The Walks on Saturday, July 3, to highlight the "urgent" need for a new hospital for west Norfolk.
The roof of the QEH is currently being held up by almost 200 props, yet it was not included in a list of hospital rebuilds announced by the government in October.
Its risk register warns there is "a direct risk to life and patients, visitors and staff" and the hospital hopes it will be one of eight further new builds chosen from a shortlist of 16 later this year.
Mr Corbyn was among those speaking at the rally on Saturday after he was contacted by Jo Rust, secretary of King's Lynn Trades Council, about the situation.
He said: "This isn't the only hospital which has this building and construction problem.
"They have to urgently deal with that, either by replacing the roof if that can be done, or rebuilding the whole hospital, which sounds the more likely option.
"But it is about ensuring all patients are safe. If you or I lived in a house where the roof is in danger of falling in, unless we had scaffolding holding it up, I think we would do something about it and probably move out.
"The same thing applies to NHS patients, they have to be cared for and they have to be safe.
"Already there have been occasions when the ICU was closed down in order to move patients out because they were worried about the safety.
"It's urgent, it's got to be done."
In March we launched a campaign to see the QEH rebuilt, and a petition which has been signed by more than 7,500 people.
A Department for Health and Social Care spokesman previously said the government "fully recognises" the need to invest in health infrastructure.
Speaking to those gathered in The Walks, Mr Corbyn said: "Frankly I'm just astonished, you've got 200 props holding up the roof of the hospital that has so far been inspected, the rest is going to be inspected as I understand it and therefore there is going to be a growth in props.
"This is the 21st century, this is absurd."
GP Dr Pallavi Devulapalli spoke of recent demand on the region's hospitals, saying there was a high percentage of bed occupancy across the sites in the last quarter.
She added: "Without the QEH the people of west Norfolk literally have nowhere to go if they need a bed.
"With this in mind, it seems shocking that we have to stand up here and ask for a new hospital to be built.
"This hospital is crumbling in front of our eyes."
Gordon Taylor, from Unison, said it fully supported the QEH campaign and branded the current situation "unacceptable", highlighting how staff and patients see "scaffolding, poles and wooden beams" across the wards on a daily basis.
He added: "No promises have been made for a new hospital. The QEH in King's Lynn needs to be rebuilt and this community needs a new hospital.
"If we secure funding, work would not be done until 2025 so we're four years down the road before possibly starting to build a new hospital.
"This town and community needs a new hospital, not in 2025, not in two years or next year. It needs something to be done now."
Ms Rust said: "Patients are having to go to bed, looking at props and wood above them.
"Imagine having to go to work every day walking down corridors that are held up with props and wood.
"Our NHS staff have worked their socks off through this pandemic and yet they are going to work on a daily basis in unsafe conditions."
The QEH was given £20m in government funding to help with structural problems and board papers revealed that extra wards and operating theatres will be created using that money.
Here's what supporters at the rally had to say:
Fabia Pollard, chair of Unison West Norfolk, said: "Lots of my family and friends work at the hospital and I know the conditions they are working in, no-one should have to work like that."
Adele Smith, whose daughter works at the QEH, said: "At the moment we are wanting to raise the profile of the situation.
"The hospital is being held up by 200 props and is going to take a long time to repair."
She said more people need to hear about the campaign and support it.
Ashley Foster, 34, a member of GMB Union, said: "It's dreadful, if it was the Houses of Parliament it would have got rebuilt by now.
"It is in such a bad state."
Philip Wagstaff, 70, said: "It is the only hospital in the area. It's a complete shambles. Norfolk is a nightmare county to get to one place to another.
"It only takes one accident and Norfolk comes to a complete halt. It's absolutely essential we have a working hospital.
"The hospital has been falling apart before our eyes for a long time and for it to not be included on the list is mind boggling."
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