"This designation - shared by substances such as asbestos and tobacco - reflected the strength of the evidence linking these products to colorectal cancer."
"A decade on," the scientists write, "we ... register our profound disappointment that decisive protective measures have not been taken in the UK... there has been no meaningful phase-out of nitrite use, no mandatory front-of-pack cancer warning to inform consumers, and little support for producers to transition to safer alternatives."
The scientists - including Professor Chris Elliott OBE of Queen's University Belfast and Professor Denis Corpet of Toulouse University - say Britain risks falling behind the rest of Europe where scientists are looking to ban or limit the use of nitrites in meat.
"The UK has a strong record in public-health leadership - notably in tobacco control - and can once again set a global standard," the letter continues. "It is therefore concerning that no satisfactory action has been taken on nitrites in processed meats, nor a commitment from the UK Government to follow new lower limits, which come into force this month across the European Union.
"Further delay will consign avoidable cancers to future patients and their families. Scientific evidence and public-health ethics demand transparency and action."