Crisis-hit A&E department tells 999 ambulance crews: Ring first to see if we've got space or we won't let you inÂ London Ambulance Service made warning over struggling emergency unit Paramedics now can't take patients directly to Northwick Park in Harrow Only London hospital which has the 'call ahead' arrangement in placeÂ Move came after closure of emergency treatment in two nearby hospitalsÂ By Stephen Adams Health Correspondent For The Mail On Sunday Paramedics have been told to ring ahead before taking patients to an A&E struggling to cope after the closure of departments at two nearby hospitals. In the latest blow for health bosses who claimed their massive hospital reorganisation programme would improve care, the London Ambulance Service has put out the warning over patients being taken to Northwick Park in Harrow. Two weeks ago, The Mail on Sunday revealed that the same hospital was experiencing the longest waits in the country following the closure of casualty units at West Londonâ€™s Central Middlesex and Hammersmith hospitals. The London Ambulance Service put the 'call ahead' arrangement in place at Northwick Park Hospital in Harrow, London, following the closure of two casualty departments in nearby hospitals (file photo) Paramedics would usually take patients to the nearest department, but this is no longer necessarily the case at Northwick Park. A spokesman for London Ambulance Service confirmed the â€˜call aheadâ€™ arrangement was now in place, saying: â€˜We are working with the hospital, so before crews go directly to Northwick Park, they need to call our control room.Â They are then advised if that is appropriate.â€™ It is the only London hospital with such an arrangement. According to official guidelines, ambulances should have to wait no more than 15 minutes outside A&Es to drop off patients, but at a meeting last week, Northwick Park executives admitted this was exceeded hundreds of times at the site in September alone. Crews had to wait because there was either no room in A&E to take the patients, or there were no staff free to care for them. The waiting not only affects patients already in the ambulances, but also ties up crews urgently needed elsewhere.Â The Mail on Sunday has revealed that Northwick Park has been experiencing the longest waits in the country In September, ambulances had to wait outside Northwick Park for more than half an hour on 179 occasions. Of those, 30 patients had to wait more than an hour. Brent Council leader Muhammed Butt said his worst fears about the effects of closing local A&Es were coming true. â€˜Immediate action needs to be taken to resolve this as we are talking about life-and-death emergency treatment. Our residents deserve the best healthcare and we need to understand why the reconfiguration of local health services has been botched so badly.â€™ The Mail on Sunday has campaigned for two years to keep A&Es open nationwide, pointing out the problems that health bosses frequently gloss over. Meanwhile, more than 20 health chiefs from West London have just flown to the United States on a week-long â€˜fact-findingâ€™ mission â€" at a cost of more than Â£5,000 a head. The taxpayer-funded trip to New York, Boston, Richmond and Baltimore began yesterday, with 22 officials due to visit â€˜innovative organisations renowned for excellent community care and partnership modelsâ€™, according to an official briefing. Andy Slaughter, Labour MP for Hammersmith, said: â€˜People will see it as extraordinary that during an A&E crisis, senior management are jetting off on a jolly.â€™