But doctors and MPs say closureis necessary to improve services

The crowds at the Emirates Stadium are angry. Really angry. But this is not another gloomy day for Arsenal as the league title slips from their fingers. In fact, there are no footballers on the pitch at all.

The people gathered yesterday have far more serious business than football on their minds. They have turned out in their hundreds to establish a battle plan against proposals to close a children's heart surgery hospital: Royal Brompton and Harefield NHS Foundation Trust (RBHT).

How do you close a children's heart surgery hospital without coming across as the devil incarnate? The answer is you don't. But this is precisely what will happen in London, and four other cities, by 2013.

Catherine Quinn, 40, is here with her son Daniel, four, who has already undergone 11 operations. He will need surgery every three years, for the rest of his life, which could happen at the Brompton because unlike the Great Ormond Street Hospital, it caters for adults too. "I don't see why Daniel should change hospitals now, and then again when he turns 16. He spent the first 10 months of his life there; it's become like a giant family to us."

Parents, doctors, nurses and campaigners have all turned up at Arsenal's football ground to talk about proposals to close one of London's three children's cardiac surgery centres. It is part of a vision to improve the safety and quality of care for babies and children born with heart conditions across England by concentrating experts and operations in fewer centres.

Closing any NHS service can be political suicide, but children's heart surgery would be in a class of its own. Which is why more than eight years after the inquiry into the Bristol babies scandal recommended this reduction, there are still too many, 11, some run by only a couple of specialist surgeons.

The strange thing is that all health professionals, and politicians, agree that larger, specialist centres are superior and safer for children, so inevitably some must close. But, and it's a big but, no one wants to be the one to go. So despite the clinical consensus, and an attempt by politicians to stay out of it for once, temperatures are running high.

Especially in London, where Great Ormond Street (GOSH) and Evelina Children's Hospitals (at Guy's and St Thomas') were identified by the "Safe and Sustainable" review as the preferred survivors over Royal Brompton and Harefield – before the public consultation started in February. Angry cries of "foul play" echoed across south-west London, followed by an application for a judicial review of the whole process issued in March.

Joan Davies, chair of the NHS pressure group Community Voice, triggers the day's first round of applause. "What jiggery-pokery is going on underneath this proposal, because it smacks of political interference and surgical jealousies?"

Dr Gillian Halley, an RBHT pediatrician, claims the review process is "fundamentally flawed" and wants access, so far denied, to the hard evidence used to score the hospital's research and innovation as "poor". "This is not a consultation; it is a white-wash. I took the Hippocratic Oath, first to do no harm, and this will inevitably cause harm. Closing cardiac surgery will close the whole hospital; you'd be a fool to think otherwise."

Eight in every 1,000 babies are born with a heart defect. About half will need surgery, which means 3,500-4,000 paediatric operations every year. Safe and Sustainable says each centre must have at least four surgeons, perform a minimum of 400 operations, ideally 500, a year, and that no child should have to travel more than three hours for treatment.

Staff and patients are maddened because RBHT meets these criteria. But the review committee says London must feel some of the inevitable pain because sick children cannot travel hundreds of miles from Bristol or Yorkshire or Liverpool, and RBHT's closure would be the least painful option.

Today's expert panel includes Professor Roger Boyle, and Mr Leslie Hamilton, past president of the Society for Cardiothoracic Surgery. They are trying to reassure the audience that this is not about saving money and will make care better.

"I'm sorry, but people should not have to travel to London for life-saving treatment," says Professor Boyle. Mr Hamilton adds: "This is not about closing bad centres. It's about getting world-class services right across the country."