RTE presenter Ryan Tubridy has called on the Government to "have the decency" to provide the funds to keep Childline running at full capacity next year.
The Irish Society for the Prevention of Cruelty to Children's (ISPCC) 24-hour helpline faces night-time closure unless the charity can bridge a large funding deficit.
Tubridy, a long-standing supporter of the charity, urged Taoiseach Enda Kenny (inset) to "man up" and back the charity.
The charity said the 45,000 calls it currently answers by night will go unanswered next year if immediate funding is not raised.
Speaking on his 2fm radio show, Tubridy said the kind of money the charity needs is "probably the equivalent of 20c on a given week" for the Government.
"That's where the Taoiseach needs to come in. We don't see too much of him but it's time to man up, stand up to this thing and put your hand in your pocket at a governmental level," he said.
"Get these people out of a hole so children aren't spending the next four or five weeks getting an engaged signal at the end of their phone when they're in trouble."
The charity needs to find an additional €870,000 on top of the €330,000 it has already raised in order to retain the 24-hour service.
In many cases the late night calls received are from children who cannot call at other times of the day due to their domestic circumstances, according to the charity.
They said the children can be experiencing "serious abuse, fear, isolation and confusion".
The broadcaster called on the Taoiseach to step in and help the charity over the Christmas period.
"Hopefully, this isn't a dark stain on this Government's copybook," he said.
"It can't be that much of a problem for them financially and the least [the Taoiseach] could do is have the decency to confront the issue and fix it."
The Minister for Children has indicated he may intervene to save as much of the charity's 24-hour service as possible.
He told the Dail he has asked departmental officials to meet with the ISPCC and Tusla, the child and family agency, "to examine how best such a service can be provided".
Tubridy's comments come after Childline fund-raiser Monica Rowe wrote to the Taoiseach expressing her anger after emergency funding of €2m was found for some of the country's biggest museums while nothing was being done to help Childline.