NHS leaders have written to new prime minister Rishi Sunak warning him not to “watch while the health service crumbles”.
Mr Sunak has been asked by NHS leaders to not ask for further savings from health budgets which have “no fat left to trim.”
The NHS Confederation, which represents trusts and GPs across the country, warned the prime minister that patient safety will be “at real risk” if more cuts are introduced.
The letter, sent by chief executive Matthew Taylor and chair Lord Victor Adebowale said: “While understanding the complexity of the current economic challenges, our members also feel trepidation in the face of touted cuts to public services.
“Without proper funding and support for the NHS and social care, and the communities they serve, NHS leaders are concerned that your ambition for a more prosperous country will not come to fruition.”
It added: “As you acknowledged over the summer, the challenges facing the NHS - many of which are outside of the services control - are unprecedented. This includes rising treatment backlogs, slipping waiting time standards, increasing staff vacancies, the growing threat of industrial action, and a social care system at the brink of collapse.
“These concerns are intensifying as we head towards winter and as prime minister, it is important that you begin your new role with your eyes wide open.”
The NHS Confederation has called on the prime minister to commit to a fully funded long-term workforce plan for the NHS - something that the Treasury had reportedly fought against when Mr Sunak was chancellor.
Mr Sunak enters Downing Street ahead of looming NHS staff strike action, with nursing unions set to make their decision following a ballot next week.
NHS Confederation has warned staff are “exhausted” and told the prime minister his tenure could be defined by his response to the threat of industrial action.
The organisations called for social care funding and said the £500 million hospital discharge funding, announced by former health secretary Therese Coffey last month, has yet to reach any services.
The letter added: “There are 165,000 vacant roles across the social care system in England, which our members and partners tell us are being compounded by poor pay in the sector and are leading to more people choosing to move to more competitive industries.”
Recent NHS data showed the cost of fixing the backlog in repairs to hospital buildings now exceeds £10 billion.
In a statement responding on behalf of No.10 the Department for Health and Social Care said:“There are over 3,500 more doctors and over 9,100 more nurses working across the NHS compared to last year.
It said the government was on track to deliver 50,000 nurses by 2024. However, a previous report by The Independent has revealed NHS modelling this year predicted the target will be missed due to the number of nurses leaving the workforce.
The DHSC added: “We have commissioned NHS England to develop a long-term workforce plan to help recruit and retain more staff and have launched a taskforce to increase international recruitment across the system this winter.”
The government is yet to confirm whether the long-term workforce plan will be funded.