Doctors have raised concerns about plans for a new cancer centre in Cardiff.
Around 57 cancer experts have called for an independent review of the plans for the new Velindre cancer hospital on land north of Whitchurch.
The new facility is planned to be built on a greenfield site, known locally as the Northern Meadows, as a replacement for the 60-year-old Velindre Cancer Centre.
But the doctors allege that the new £180m centre would not be fit for purpose and that a more integrated service with a general hospital would be better as modern cancer treatments need a range of services on-site, including surgery and intensive care.
There have been demonstrations and an online petition to try and save the meadows attracted thousands of signatures.
Now a letter from the doctors states that while they are "committed to transforming cancer care for patients in south east Wales" and they believe there is an "exceptional opportunity to get this right" that the new centre would not be fit for purpose.
Velindre University NHS Trust has agreed to seek independent advice.
Addressing the claims, Steve Ham, chief executive said: " The Transforming Cancer Services programme is intended to build upon our existing high quality services across south east Wales and seeks to further improve the way in which we collectively deliver cancer treatment.
"It will ensure that all patients at all stages of their pathway have safe and effective care, equity of access to treatment and safe management of toxicities of treatment or disease wherever they live."
He added: "Plans to develop the new Velindre Cancer Centre were supported by health boards in 2018 as part of our work to transform cancer services across south east Wales. They were developed in partnership with health boards, engaging hundreds of clinicians, patients and partners and have been subject to scrutiny and independent review.
"We are aware of the matters raised by clinicians regarding a number of areas where they believe there is still work to be done in designing future services.
"We are continuing to work with our patients, clinicians and health board partners to further strengthen the model to ensure it is always fit for purpose. This will include independent external advice.
"We, like all our colleagues across the south east Wales area, have the interests of our patients at the heart of everything we do.
"We believe that the future model will improve the quality and safety of care; enhance patient experience; and improve the equity of access to treatment and research."
A Welsh Government spokesperson said: “We are committed to improving cancer services in Wales. The Minister has responded to this letter confirming that Velindre University NHS Trust will seek independent advice on the clinical model for the new cancer hospital.
"The Chief Medical Officer is also discussing the management of acutely unwell cancer patients with health board medical directors to ensure the current model of delivery is fit for purpose."
Steffan Webb, from Plaid Cymru in North Cardiff, said: "This is further evidence that this is the wrong hospital, in the wrong place, at the wrong time.
"It is very brave of the doctors to speak out and we are grateful to them. It now needs to be called and for there to be a debate in the Senedd about the plans. We need improved cancer services in Cardiff, but it needs to be a more integrated approach."
