Comprehensives have failed to break the link between poverty and poor educational achievement, the education secretary has told Labour delegates.

Irresponsible parents and truanting or unruly pupils were also in Estelle Morris's sights when she addressed her party's conference in Blackpool on Wednesday.

Morris joined Tony Blair in calling time on the one-size-fits-all comprehensive model.

In a move echoing the Labour leader's attack on the link between social class and educational results, she led an "anti-elitist" call to tackle the middle-class monopoly on achievement.

"We still face profound challenges," she said. "At all levels of our education system there is an unshakable link between a child's background and what they achieve at school."

"The link between social class and poverty is still strong."

Morris took on "old" Labour dissenters who are concerned the government is set to resurrect grammar schools and academic selection by killing off their beloved comprehensive idea.

She said the ideal had achieved much but failed to live up to expectations.

"I believe in the comprehensive ideal," she told delegates. "But it has not delivered everything I wanted. It hasn't achieved all that we campaigned for.

"I thought it would break the link between poverty and achievement. It hasn't. I hoped it would end the massive under-achievement of ethnic minorities. It hasn't."

Speaking to an audience including many teachers, Morris set out a "post-comprehensive era" of more consumer choice for parents.

"We can settle for what we have already or we can have the courage to reform. I tell you what mean by the post-comprehensive era. It cherishes the values of opportunity and worth, but its honest about its strengths and weaknesses and brave about where it goes next," she said.

She will later be joining the prime minister on a high profile visit to a specialist Blackpool sports college.

The former PE teacher declared her intentions to increase diverse school provision and "ensure that the education of every child is focused on their individual needs and on building on their talents".

"That's what we mean by getting rid of "one-size-fits-all. Each area, each pupil is different. So we need different types of schools to meet their needs," she told Labour.

Against the backdrop of the A-level exam fiasco, Morris targeted school skivers and classroom yobs - warning that the mothers and fathers who allow them to skip classes or fail to tackle bad behaviour must toe the line.

"There is a minority who misbehave and are out of control. And they make life a misery for teachers and their classmates," she said.

"Teachers cannot teach if children are disruptive. One child threatening or abusing one teacher in one of our schools is one too many."

"One child showing just disrespect to a teacher is one child too many."

Downing Street's top crime summits have identified truancy as a key factor boosting soaring street robbery figures.

Morris recently backed the controversial jailing of an Oxfordshire single mother who had repeatedly allowed her daughter to stay away from school.

"We have a choice. The easy choice is to say nothing can be done. It is a sign of the times. We can choose to be a society that throws its hands up in horror but is unwilling to do anything about it," she said.

"Or we can give a clear message about the behaviour we expect from our pupils. We must back teachers and make parents take responsibility."

Morris told delegates that much more must be done to make parents take their responsibilities seriously - before truant children become trapped in a cycle of criminal activity and missed education opportunities.

"Although almost all parents support teachers, the small numbers who do not, damage their children's future. I hear too many stories of parents questioning a teacher's right to exercise discipline in the classroom. It has to stop."

"Parents have rights", she acknowledged, but responsibilities too.

"They should know how a school performs. They should always be able to question what is going on. But they have responsibilities as well. And if they do not exercise those responsibilities, then they will have to face the consequences."