THE future of Leeds children’s heart unit is in fresh doubt as it is poised to be ordered to meet tougher standards – or close.

Health chiefs have drawn up new rules to decide which centres should remain open, to settle a bitter, decade-long controversy which, they admit, threatens safety and quality.

In theory, all ten units across England - including at Leeds General Infirmary, which serves Bradford - could survive the shake-up, proposed by NHS England.

However, a fresh battle for survival is likely, with the new standards including:

* That each unit has at least four heart surgeons, to provide treatment around the clock and cover for staff absences.

* That every surgeon carries out at least 125 operations a year, averaged over three years, to ensure they build up expertise in the complex procedures.

Last night, Leeds General Infirmary acknowledged it had only three surgeons, although it said funding was already in place for a fourth.

It carried out only 336 operations in total in 2012 - when a minimum of 500 would be required - but that was more than at Newcastle (247) or Leicester (212).

Greg Mulholland, the Liberal Democrat MP for Leeds North West and a key player in the fight to reprieve the Leeds unit said he was “upbeat”.

He said: “Leeds is well-placed to have four surgeons and the additional capacity, while other centres are struggling to find enough patients. So many people rely on it.”

A spokesman for NHS England said: “There is a general consensus that four surgeons is the minimum, to provide enough cover when someone is on holiday or called away on urgent business.

“And 125 operations is the minimum each surgeon needs to carry out each year in order to keep their skills up to date and to ensure they are working on the most complex cases.”

The fresh consultation comes 15 months after Health Secretary Jeremy Hunt scrapped plans to concentrate surgery in seven centres and axe three others – including Leeds.

To the jubilation of campaigners in Leeds, Mr Hunt accepted the conclusions of an independent panel that the closure plan was “based on a flawed analysis”.

However, concerns about babies dying unnecessarily - because doctors carry out too few operations to build up the necessary expertise – date all the way back to 1989.

Now families, charities, MPs and hospitals have until December 12 to make their views known, including at an event in Leeds on November 3.

Leeds Teaching Hospitals NHS Trust said: “We currently have three surgeons undertaking children's heart operations and have funding in place for a fourth if they are required.

“Our surgeons all currently do in excess of 125 cases each every year.”

The other expected standards include communication with patients and their families, the transition moving between child and adult services and providing other healthcare services.