Children’s heart surgery at Leeds General Infirmary will restart on Wednesday, NHS England today said.

Operations were halted at the unit last month after concerns were raised over death rate data and other issues - a decision that provoked anger, surprise and dismay from campaigners who had been fighting to keep open the threatened centre.

Last week, after a series of high-levels meetings, the hospital announced it would be allowed to restart surgery if a team of experts gave the necessary endorsements.

Today, in a statement, NHS England said: “Children’s heart surgery at Leeds General Infirmary can begin a phased restart on Wednesday.”

NHS England said it originally raised concerns about services at the LGI because of preliminary data suggesting high mortality, concerns about staffing levels, whistleblowing information from clinicians, and complaints from patients.

Its statement today said the decision to start a phased resumption “follows completion of the first-stage of a review by a multi-disciplinary independent clinical team, which has been working to establish the immediate safety of the unit.

“NHS England has accepted the trust’s recommendation, supported by independent experts, that surgery should resume gradually over the next month, starting with lower-risk cases.

“The second stage of the review will now begin looking at other areas where improvement may be necessary.”

It said this second stage will involve a review of the way complaints from patients are handled and completion of a review of patients’ case notes over the past three years.

The statement went on: “NHS England will further explore issues that have been raised about referral practices to ensure they are clinically appropriate.

“During the first stage of the review, NHS England received assurances from independent experts about the quality of surgery and staffing levels that were sufficient to allow the phased resumption of operations.

“However, it has asked for significant improvements to the way the unit monitors the quality of care so it can be compared with similar services. The review found that the trust’s data for monitoring surgical results was uniquely poor, triggering concerns about death rates and gaps in information.”

Sir Bruce Keogh, the medical director of NHS England, said: “The information that came to light about Leeds raised some really serious questions and action had to be taken.

“The trust agreed to pause surgery until these questions were investigated.

“If we have learned anything from public inquiries such as Bristol and Mid Staffordshire it is that patients were harmed while organisations argued about the veracity of data used to measure clinical results, rather than addressing the underlying issues.

“We would not have been forgiven if a child had died or suffered unnecessary harm while we sat on our hands.

“I am pleased that we have now been given assurances by independent assessors that the immediate safety concerns, which were bubbling up from a variety of sources, have been addressed and that the unit can recommence surgery.

“We now need to explore some of the wider issues around how the unit operates as a whole. I hope we will soon be able to give the unit a full clean bill of health beyond this immediate reassurance of safety.”

Sir Bruce said: “I want to be clear that NHS England will do everything in its power to make sure that measuring clinical outcomes will be given priority in the new NHS.

“Organisations cannot know they are providing effective or safe care unless they are measuring and monitoring their services.”

The Leeds centre has been earmarked for permanent closure following a nationwide review of children's cardiac services in England.

But the campaign group organised to fight that decision won a major victory in the High Court just a day before NHS England arrived in the city with concerns about the unit which forced the suspension of surgery.

Many of those involved in the campaign raised concerns about the timing of the intervention - just a day after the judge's ruling.

On Friday, after a week of controversy, arguments and high-level meetings, an announcement was made that operations could be resumed early this week "subject to independent validation of the clinical data and an external review of clinical governance processes".

Experts have worked through the weekend to provide the necessary endorsement.

Surgery was suspended by the hospital just before Easter after an intervention by Sir Bruce who said later that death rate figures were among a "constellation of reasons" the decision was made.

But medical bodies, doctors and other experts questioned the accuracy of the data used to support the suspension of surgery.

A Department of Health spokeswoman said on Friday that Health Secretary Jeremy Hunt would support a decision to reopen the unit if the original concerns had been addressed.

The suspension of surgery provoked a wave of debate culminating in some Leeds MPs calling for a high-level review of what happened over the last two weeks.

Greg Mulholland, Liberal Democrat MP for Leeds North West, said there had still been no proper explanation as to why the unit was closed and demanded those responsible were held to account.

Leeds Teaching Hospitals NHS Trust said the review of its services found no evidence of significant safety concerns and a number of positive aspects.

The trust said a further analysis of paediatric surgical mortality data concluded there was no safety problem in Leeds or in any other children's heart surgery centre in England.

Maggie Boyle, chief executive of the trust, said: "We stated on Friday that we wished to restart surgery once our partners were as confident in our staff and services as we are.

"I am delighted to say we are now reopening the unit having had the quality of our service independently verified by the Care Quality Commission, NHS England and the NHS Trust Development Authority following a rapid review process which took place over the weekend."

Ms Boyle continued: "We are aware of the upset and worry this process has caused to our patients and families as well as the dedicated staff of the unit.

"We can only apologise on behalf of all concerned for the worry and uncertainty they have suffered as a consequence of this process.

"Our partners and ourselves are now in a position to reassure those families coming to Leeds for treatment that our hospital is as safe as any children's heart surgery centre in England."

The trust thanked the families, stakeholders and staff for their continued support and understanding.

The Save our Surgery (SoS) campaign group said it was relieved the unit was to reopen but had numerous concerns about the decision to close the unit after the High Court judgment.

An SoS spokeswoman said: "Save our Surgery is relieved that the children's heart unit is to reopen, ending a very difficult period for all connected to the children's heart surgery service at Leeds General Infirmary.

"We hope patients and their families will feel reassured that the unit has been proven to be performing at the highest standard.

"Our main focus since the suspension of the service has been on ensuring surgery resumes as quickly as possible, however we do have numerous concerns about the chain of events that led to this decision.

"We seek urgent reassurance from the Secretary of State for Health that actions taken were in no way related to our High Court judgment the previous day, and we call for an investigation into how unverified mortality data and 'rumblings' from parties with an interest in the outcome of the judicial review could have led to the unit being shut so dramatically."