The research suggests alarming numbers of four- and five year-olds could be behind in a range of ways, including delayed speech and social skills.
Some of the 1,100 respondents to The State of Education survey, carried out by schools support service The Key, blamed mobile technology’s intrusion on family life and one primary school headteacher said, ‘Four-year-olds know how to swipe a phone but haven't a clue about conversations.’
The report highlights how 79 per cent of concerned teachers saw ‘lack of social skills’ as a top issue and 78 per cent said ‘delayed speech’.
‘Deficient self-help skills’ and lack of resilience was cited by 69 per cent of the school leaders.
Some 58 per cent said underprepared pupils are arriving with below par reading skills, 56 per cent highlighted writing standards and 55 per cent were disappointed by numeracy.
The headteachers estimated 194,003 reception children were not at the expected level, amounting to just over 30 per cent of the total of 636,761.
One school leader said, ‘Why, in the 21st century are children still arriving in school nurseries aged three or above without being toilet trained?'
Another said, ‘We are having more and more children entering our early years stage with delayed speech and a lack of school readiness.
‘I feel much of this is down to challenging family circumstances alongside the rise of mobile phones and other mobile technology, which means parents are more often to be seen on the phone than talking to their children.’
Source: The Key, State Of Education survey 2016
Almost all - 99.5 per cent - primary school leaders said some pupils are joining school below the level of school-readiness they expect. Some 31 per cent believe half of their new starters are arriving underprepared. This means fewer than one in 100 leaders consider all of their pupils to be at the expected level when they start.
Octavia Holland, director of children’s charity The Communication Trust described as ‘deeply worrying’ the findings on speech delay, and called for more support in the early years.
She added, ‘We know that early language is crucial to a child’s development and it underpins a child’s ability to learn, form good relationships and achieve their potential, government needs to take note of these findings and review support for language for under-fives.
‘The Communication Trust believes a relentless push for high quality childcare, stronger opportunities for supporting a child’s language development before they reach school and better support for parents are essential, particularly for the most disadvantaged.’
The findings come shortly after baseline tests, intended to measure the abilities and progress of all reception-class pupils in English state schools, were dropped because they were found to be unreliable.
Fergal Roche, chief executive officer of The Key, raised concerns over the additional burden on teachers and called for an agreed definition of ‘school readiness’.
He said, ‘It’s predicted that 336,000 more children will enter primary school by 2024 - almost half of whom will be entering in the next couple of years.
‘School leaders are already struggling to retain staff and manage their teachers’ workload, so add thousands more pupils arriving ill-prepared for the classroom to the equation, and the burden placed on our schools will be huge.
‘To lessen this load more should to be done to ensure children are arriving at school with the skills they need to learn.
'An agreed definition of what "school-readiness" means, could be the first step to helping schools, parents and early years practitioners identify what national or localised support is required to meet this growing issue.’
The report can be downloaded here.