Dr Andrew Stein, a kidney consultant, runs a guide for patients on how the NHS works and worked on a 2013 NHS report which discovered that patient outcomes were affected by the day of the week. Speaking on BBC Radio 4, Dr Stein said the NHS ‘will not function’ nor ‘hit any target’ until it operates seven days a week.He said: ‘People start heading to the car parks at 12 and by 2pm it’s all quiet and the hospital is not used to full capacity through the weekend.'[CT scans] are not done, operations are not done. So just getting more staff in and using more money doesn’t necessarily solve that problem because that’s an efficiency problem.’It comes at a time new figures showed the NHS is facing a backlog of 7.07 million patients, with performance against cancer at record lows.Last month, heart attack and stroke victims were likely to wait for over an hour for an ambulance.NHS patients were also 25 percent more likely to remain in hospitals on weekends compared to weekdays despite being fit to leave. NHS hospitals are not being used at ‘full capacity’ seven days a week claims Dr Andrew Stein (Image: Getty Images) It comes at a time new figures showed the NHS is facing a backlog of 7.07 million patients (Image: Getty Images)Dr Stein’s comments have been opposed by the British Medical Association and NHS leaders who have said there are not enough staff for current work schedules.Chairman of the British Medical Association, Dr Vishal Sharma, said: ‘Hardworking doctors and NHS staff will not recognise the description of the NHS being ‘like the Mary Celeste on a Friday afternoon.”These comments are hugely disrespectful and very disheartening when the truth is that the NHS is under extreme pressure and staff are routinely having to work above and beyond to provide care for their patients.’Dr Sharma said it was true that less planned and non-urgent work happened at weekend, however, he added: ‘The fundamental issue is that there is not enough staff during the weekdays, let alone across seven days’.READ MORE: Badenoch seeks to boost UK-US trade links during trip to Washington DC Jeremy Hunt, the Chancellor and former Health Secretary proposed a seven-day in 2015 (Image: Getty Images) It comes at a time nurses have voted for their first ever national strike (Image: Getty Images)The Chief Executive of the NHS Confederation, Matthew Taylor, also commented on the issue and said: ‘The NHS is there for everyone who needs it every day of the year, including primary care, carrying out well over one million appointments most Fridays and urgent and emergency care services routinely being busier over weekends than during the week.’While many trusts would like to provide more non-urgent services over the weekend like some elective care, they simply lack the staff to do so.’Mr Taylor said the problem was ‘the failure of successive governments to provide a fully funded workforce strategy to help tackle the NHS’s 132,000 vacancies, to address the maintenance backlog of £10 billion, and to provide proper support for social care, with local communities and frontline staff all paying the price’.DON’T MISS:Prince Andrew ‘determined to fight’ as he looks for public life return [REVEAL]Meghan and Harry human rights honour labelled ‘sublimely ridiculous’ [REPORT]Taylor Swift wows in plunging bodysuit and sheer net skirt for EMAs [INSIGHT]Jeremy Hunt, the Chancellor and former Health Secretary proposed a seven-day week in 2015 which led to the junior doctor’s strike in 2016.Mr Hunt argued that studies showed a ‘weekend effect’ in the NHS and said patients admitted to hospital on Sunday were 15 percent more likely to die than on Wednesday.The British Medical Association accused Mr Hunt of a “wholesale attack” on doctors and called on the Government to say how they would fund the change.At the time, the council chairman of the British Medical Association Dr Mark Porter said: “Despite whatever the Health Secretary may claim, his simplistic approach ignores the fact that this is a much broader issue than just doctors’ contracts.It comes at a time nurses have voted for their first national strike and other health workers may be on strike before Christmas.A former senior health source told the Telegraph it was not the right time to debate this issue due to the current strike concerns and said: ‘For people that were wavering, I think it would just put petrol on the fire.’