Parents hoping to delay when their children are sent to school are subject to a "postcode lottery" because of a lack of government action, former ministers have warned.
Conservative MP and former transport minister Stephen Hammond said that some schools had taken "absolutely no notice" of a letter from education minister Nick Gibb advising that there would be a consultation over when summer-born children could start school.
Others, he added, had taken this as a sign to offer greater flexibility.
Mr Gibb announced in September last year that the government intended to change admissions rules to prevent summer-born children from being forced to go straight into Year 1, providing greater flexibility for parents and teachers.
But Mr Hammond said that while most local authorities allowed summer-born children to start 12 months later, "many still demand a very high level of expert evidence".
He warned that this was a "barrier" that many parents "simply cannot get past".
'Disappointment' over inaction
Speaking during a short debate in the Commons, Conservative MP and former education minister Tim Loughton said to Mr Hammond: "The minister announced last year his intention to amend the school admissions code.
"Do you share my disappointment that nothing has happened since that last year?"
Mr Hammond replied: "I do agree. I had hoped progress might be better."
He said the letter to local authorities had been "helpful", but many had taken "absolutely no notice" of it. "So we now have parents and children across the country – and I've had emails flooding in over the last few days from people across the country – [with] radically different experiences."
Schools minister Mr Gibb said progress had been made but acknowledged work was still needed.
Mr Gibb added: "The admission of summer-born children continues to be a problem in some parts of the country and we need to do more to help parents, particularly those with genuine concerns about their child's readiness for school."
He said the planned changes to the code would come into effect once the government had collected the data it needed to ensure they would have no "unintended consequences" when they were rolled out.