Only one in four of the 730,000 calls made to Childline last year were answered due to a shortage of staff, according to new figures compiled by the ISPCC.
While the statistics represent an improvement over the previous year, when one in five calls was answered, the charity said it was concerned about the number of children who were finding it difficult to get through to the service.
Up to 20 staff and volunteers answer calls at peak times. However, ISPCC chief executive Paul Gilligan said this was still inadequate to deal with the volume of calls.
"We promise to listen to all children and our greatest disappointment is that many of these children cannot get through to us. We are determined to try to meet that challenge," he said.
The service was under most strain between after-school hours and 6pm, when there were difficulties finding volunteers, Mr Gilligan said.
The majority of calls concerned inquiries about the service (35 per cent). The next largest group of calls was for what the service terms a general chat (16 per cent). Other calls covered sexual issues (8.5 per cent), physical abuse (3.8 per cent), pregnancy (2.9 per cent) and sexual abuse (2 per cent).
Mr Gilligan said calls relating to sexuality were significantly high compared to previous years, reflecting a worrying trend of confusion and premature sexualisation. "There is massive pressure on young people to be involved in sexual activity at a young age. Over the last five years there has been a marked increase in the number of these calls, which reflects not only the lack of information and support available to young people in this area, but also the increasing sexual pressure on young people in general," he said.
As a result of the difficulties young people face in getting through to Childline, the ISPCC is to launch a new text-messaging service. This will provide an immediate, automated response to text messages sent in by children across a range of eight specific topics, including bullying, the facts of life, relationships, loneliness and suicide.
The text-messaging facility (Text 50101) is being established following consultation with young people through schools and youth organisations, which showed that 80 per cent were in favour of such a service.
Other trends which had emerged from this consultation process were the levels of boredom young people reported, the lack of recreational facilities and the sense of isolation among the young, Mr Gilligan said.
He emphasised that these issues were significant in the light of the Government's plans to introduce Anti-Social Behaviour Orders which, he said, failed to address the issue of investing in communities. "The ISPCC is opposed to these orders and believes such measures will criminalise children, something which will ultimately cost the State more and will further isolate these young people," he added.
