The future of children's heart surgery at Glenfield Hospital could lie in a report given to Health Secretary Jeremy Hunt yesterday.
Campaigners fighting to save the Leicester service described completion of the report by the Government's Independent Reconfiguration Panel (IRP) as a "significant step".
They are hoping the findings will secure the future of children's heart surgery at Glenfield Hospital.
It follows the decision by an NHS review, known as Safe and Sustainable, in July, to cut the number of hospitals offering surgery for children with heart problems from 11 to seven.
The Glenfield service was one earmarked for closure but last year Mr Hunt asked the IRP to review the decision.
Robyn Lotto, from Stoneygate, who helped collect petition signatures and questionnaires in response to a public consultation, said: "The IRP gave us the first real chance to be heard, and for that we are really grateful.
"We must now wait to see how views have been portrayed in its report and what the Secretary of State for Health does with it. I hope he moves quickly and ends this terrible uncertainty."
A spokesman for the IRP, headed by Lord Ribeiro, said the panel had more than 25 days of evidence gathering from individuals and organisations.
He said: "The IRP visited all 10 sites providing services for children with congenital heart disease and three cardiology centres in Manchester, Cardiff and Oxford."
However, it is not yet known when Mr Hunt will make a decision on the findings.
A spokesman for the Department of Health said: "The Health Secretary will consider this report in detail and make a decision in due course."
There is also uncertainty about a decision by NHS England to challenge a High Court decision in a case brought by campaigners in Leeds.
Eric Charlesworth, from the former health watchdogs, the Leicester and Leicestershire local involvement networks, said: "Completion of the IRP report is a significant step as far as we are concerned.
"The panel did listen and, on the basis of the quality and depth of questions, it will be interesting to see the outcome."
Dr Aidan Bolger, a consultant cardiologist at Glenfield Hospital, said: "The panel members appeared to listen carefully to concerns about a number of details, seemingly overlooked in the original review.
"This included the lack of a meaningful measure of quality, such as the latest mortality data, which shows we have one of the lowest mortality rates in the country, the latest population estimates which show our closure would leave the Midlands woefully short of clinical capacity, and warnings from international experts that in dismantling our leading Ecmo – extra corporeal membrane oxygenation – service and trying to create a new one elsewhere, mortality is likely to increase.
"Throughout this process our priority has been to provide excellent care to patients and families and that will continue as we all now await the decision of the Health Secretary."