For more information, visit www. facebook.com/Donate4Daithi. To sign the organ donation register, visit www.organdonation.nhs.uk

However, last December his distraught parents learned he had tricuspid valve leak.

“It meant that with every pump of his heart around 20% of the blood was leaking back in, making the heart work harder,” Mairtin explained. “It ruled out another heart operation. The only option now is a transplant.”

Daithi is on the routine heart transplant register and is being assessed every six months, but time is of the essence.

“Normally, children get anoth- er heart operation between two and five,” Mairtin added.

“We don’t know how long he can keep fighting, but if he doesn’t get a heart in the next couple of years, we will lose him.

“Day to day life can be stressful, but he gives us the strength to go on. He is always smiling, laughing and full of joy — he makes me proud every day that I’m his daddy.”

Mairtin praised the positive reaction of the local community to his appeal to put youngsters on the organ donation register.

“People are even getting in touch saying unborn babies are donors,” he revealed. “Daithi is also a donor.

“A lot of parents don’t know that they can put their kids on the organ donation register.

“Daithi could get a donated heart from a child aged two to six. It must be so hard for other parents to imagine life without their children — we didn’t have that choice. The potential of that gift is unbelievable.”

Mairtin would like to see a ‘soft opt-out’ organ donation system implemented here, whereby people are automatically considered donors, but families have the last say after death.

“We hope to save Daithi’s life, and the lives of other babies,” he said.