More than 1,000 people have signed an online petition stop children's heart surgery being moved from Leeds General Infirmary.
All 11 children's heart surgery units in England are being reviewed by health bosses. Some units will stop performing operations because they say having fewer, bigger units is safer and surgeons could do more procedures.
An NHS review team is expected to draw up its recommendations over the summer, with a public consultation due in the autumn.
Concerned parents in Leeds have launched a petition over at thepetitionsite.com - and have so far received 1,032 signatures in just less than a month.
Mother Kerry Singleton, who started the petition, fears parents and children may be faced with a long trek to another hospital - and that stopping operations in Leeds could lead to fatal consequences.
She says on the site:
"They say this is to make fewer but better centres, however this will cause lots of problems, the most serious one is that it will cost lives in the long run.
"Critically ill children need to be in hospital as soon as possible and to travel them, say, 300 miles, as opposed to 70 miles could be deadly. The effects will just go on and on, we must stop this from happening!
"Hundreds of families will be affected by this, including myself with our daughter, who will have to then travel to say London/Newcastle for surgery. This will cause massive implications to all the heart families, it will mean no added support from friends/family, further to travel, extra expense, not to mention the risk of a critically ill child having to travel all that way.
"Having a child go through heart surgery is more stressful than I can explain, without the added worry of been at a hospital at the other side of the country. Save heart surgery at the LGI and don't cut lives!"
Recent signatories to the petition include:
Andrew Knowles, who wrote:
"My son had fantastic treatment for a congenital heart defect on ward 10 LGI at two years old and is now a clever, bright, polite, handsome nine year old with a big future thanks to all the staff. We were able to stay on site and comfort him through a traumatic time and we received excellent support from all those superb people.
"We were fortunate that Leeds is only an hours travelling time from our home which is vital for a child when travelling home from this sort of exhausting surgery."
Kelly Oliver wrote:
"I know without this ward and staff I wouldn't have my brother here with me today. This is why I have signed the petiton."
The Department of Health began the review of children's heart surgery units in 2008. The review is aiming for at least four surgeons doing 400 operations a year, but in Leeds there are three surgeons doing around 300.
A Facebook group run by LGI parents can be found here.
What do you think? Have your sa in the comments section below.