Some children are starting reception school “unable to climb a staircase”, while others use Americanisms in their speech because of too much screen time, according to a survey of teachers.

The pandemic has been blamed for a decline in school readiness among reception-aged children, but some teachers who took part in the annual poll said the “Covid baby” explanation was starting to feel like an excuse.

As well as children arriving at school in nappies – one in four who began reception last September were not toilet trained – teachers reported children with poor basic motor skills and underdeveloped muscles, which they linked with excessive screen use.

“I’ve got two children [in my class] who physically cannot sit on the carpet. They don’t have core strength,” a reception teacher in the north-west told researchers.