As many as 1.2million youngsters are now estimated to struggle with speech.
Half of pupils in some areas start school unable to put sentences together.
The rise is being blamed on the growing use of screen-based gadgets as convenient ‘babysitters’ and a trend for hard-working parents to spend less time with their children.
Teachers are also said to be identifying speech difficulties among pupils more readily.
Findings from a major new Government-funded study show that the number of schoolchildren needing expert help for speech and language difficulties rose 71 per cent between 2005 – when reliable records began – and 2011.
The analysis, part of the Better Communication Research Programme, found that 2.2 per cent of youngsters aged five to 16 were classed as having difficulties in 2011 – some 135,700.
But the figures do not capture pupils who are identified as having speech difficulties and are helped within their schools without recourse to specialists, for example using small group tuition.
Responding to the findings, the children’s charity I CAN said other studies had suggested that 1.2million youngsters of all ages across the UK have some form of communication problem.
They include children with specific conditions that lead to speech problems and others whose environment may play a part in their language difficulties.
The charity said that 50 per cent of children in some parts of the UK – particularly areas of social disadvantage – start school with delayed language.
Jean Gross, the Government’s former speech and language tsar and a trustee of I CAN, said the sharp rise in cases of speech difficulties was likely to be down to 21st century living, as well as better identification by parents and schools.
Screen-based technology – including TVs, games consoles, smartphones and computers – was increasingly used to occupy children instead of traditional family activities such as learning nursery rhymes and eating together, she warned.
Meanwhile both mothers and fathers were increasingly working long hours to make ends meet, forcing them to rely on childcare which can be patchy in quality.
‘Head teachers are telling me they are seeing a real increase in the number of children who struggle to string words together,’ she said.
Many reasons had been put forward to explain the trend, including the demise of family meal times and even the advent of central heating, which put an end to the days of families congregating around the fire in one room, she said.
‘Head teachers also suggest that parents are just so busy these days trying to pay the mortgage and keep things together,’ she said.
‘They may not have as much time to play on the floor with their children and talk to their children.’
This affected ‘cash-rich time-poor’ middle-class parents as well as poorer households.
In one case described by a head teacher, the parents of a five-year-old who could barely speak was given a BlackBerry as a present.
She added: ‘It’s not about parents not wanting to talk to their children but about the stresses of modern life.
‘This isn’t going to change but what parents can do is use the times they do have with their children – car journeys, bath times, meal times – to talk and listen to their children.’
She added: ‘Increased use of screen technology in all its forms is also suggested as a reason.’
Mrs Gross said television programmes could be educational after the age of two if used as a springboard for family conversations rather than a substitute for them.
She added that teachers were also thought to be ‘getting better at getting under the skin of why children are struggling with learning’.
The latest study, published yesterday by the Department for Education, found that parents may face a long wait – in some cases up to two years – to access specialist support once they have raised a possible problem with their children’s speech.
It found that children who struggle with language during their early years were more likely to struggle at school.
Early intervention was crucial, it said, yet in many primary classes there was limited use of approaches to help children’s language.
Virginia Beardshaw, chief executive of I CAN, said the research ‘demonstrates that parents are having to wait as long as two years between noticing a child’s difficulties and getting help.
‘This isn’t acceptable when every day matters to a child’s language development’.
She added: ‘We know there is a “golden window” between 0 to 5 where help and early interventions can make a material difference to a child’s language.
Early years settings and schools can put programmes and interventions in place so that children do not slip through the net.’
Edward Timpson, children and families minister, said: ‘Communication is fundamental to all learning. It is vital that children with speech, language and communication needs get the support they deserve as soon as possible.
‘The Better Communication Research Programme provides a rich and extensive source of evidence on what works in identifying the needs of children and young people with speech, language and communication needs.’