Children being sent to school unable to speak in sentences is a “persistent scandal”, the Education Secretary is to tell parents.

In his first major speech on social mobility, Damian Hinds will promise to tackle the "last taboo" in education by highlighting the fact that many mothers and fathers are failing to teach their children how to talk.

Speaking at the Resolution Foundation in Westminster on Tuesday, he will say that he has no desire to “lecture” parents about how to raise their children.

But he will warn that children who start school at age four behind their peers rarely catch up and instead “the gap just widens”.

“It is a persistent scandal that we have children starting school not able to communicate in full sentences, not able to read simple words,” he will say.

“And the truth is that the vast majority of these children’s time is at home. Yes, the home learning environment can be, understandably, the last taboo in education policy – but we can’t afford to ignore it when it comes to social mobility.

“I don’t have any interest in lecturing parents here…I know it’s parents who bring up their children, who love them, who invest in them in so many ways, who want the best for their children. But that doesn’t mean extra support and advice can’t be helpful.”

Damian Hinds will say that he has no desire to “lecture” parents credit: Eddie Mulholland

His comments follow research that shows that more than a quarter of four-and-five-year-olds lack the early communication and literacy skills expected by the end of reception year.

The ‘expected level’ includes a child having the words and understanding to talk about events that have happened or are going to happen in the future.

A separate study shows that children with poor vocabulary at age five are more than twice as likely to be unemployed at age 34 as children with good vocabulary.

Mr Hinds will say that he wants to halve the number of children starting school without the early speaking or reading skills they need by 2028.

He will outline his intention to build a new coalition of business leaders, charities, tech companies and media groups to encourage more parents to read and learn new words with their children.

Representatives from the National Literacy Trust and Public Health England will sit on the coalition, which will come up with ways to boost parents’ confidence with supporting their child’s language and literacy.

It is a persistent scandal that we have children starting school not able to communicate in full sentences, not able to read simple words

This could include awareness-raising campaigns, like the ‘Five a day’ public health campaign that encouraged more people to eat fruit and vegetables as a model for changing parents’ behaviour.

Mr Hinds will say that while there are “legitimate worries” from parents about screen time, media and modern technology, it can also be a useful tool for parents to help with their child’s language development.

The head of Ofsted has previously warned that more and more children are starting school without being able to communicate properly or even use the toilet.

Amanda Spielman described how some “lucky” children are given bedtime stories or taught the alphabet by their families, while others are not so fortunate.

She has previously urged nursery staff to spend time teaching pre-school children new language skills - whether through songs, nursery rhymes or "time-honoured classics" such as Hans Christian Andersen or Dr Seuss.

The Ofsted head said children starting their first year of school should also be able to sit still and listen, understand the words "no" and "stop", and be able to put on their own shoes and coat.