Senior public officials and councillors who fail to protect children from sexual exploitation will face up to five years in jail under a new criminal offence being considered by the Government.

Under proposals unveiled by Prime Minister David Cameron and subject to consultation, the crime of "wilful neglect" will be extended to cover children's social care and education, with unlimited fines for individuals and organisations shown to have let children down.

A new national helpline will be established to help professionals blow the whistle on failings in care for children. And senior staff who leave councils after abuse scandals could see their pay-offs clawed back if it is shown they failed to protect children under their responsibility.

The measures were being announced as Mr Cameron hosts a child protection summit at Downing Street, bringing together police, council chiefs, healthcare experts and ministers with victims and their representatives.

The summit - called in response to a series of damning reports of sexual exploitation of up to 1,400 children over many years in Rotherham - will see the Prime Minister demand that local areas work more effectively to strengthen protections for children.

 Child sex abuse has been prioritised as a "national threat", like serious and organised crime, meaning that police forces, chief constables and police and crime commissioners have a duty to collaborate with each other across boundaries to safeguard children.

Mr Cameron will say: "We have all been appalled at the abuse suffered by so many young girls in Rotherham and elsewhere across the country. Children were ignored, sometimes even blamed, and issues were swept under the carpet - often because of a warped and misguided sense of political correctness.

"That culture of denial which let them down so badly must be eradicated.

"Today, I am sending an unequivocal message that professionals who fail to protect children will be held properly accountable and council bosses who preside over such catastrophic failure will not see rewards for that failure.

"Offenders must no longer be able to use the system to hide their despicable activities and survivors of child sexual abuse must be given the long-term therapeutic treatment they need to rebuild their lives. But it is not just about introducing new policies. It is about making sure that the professionals we charge with protecting our children - the council staff, police officer and social workers - do the jobs they are paid to do.

"We owe it to our children, and to the children who survive horrific sexual abuse, to do better and ensure the mistakes of the past are never repeated again."

Last year's report by Prof Alexis Jay found collective failures of the care system, police and local politicians in their response to hundreds of cases of child sexual exploitation over a 16-year period in Rotherham. It was followed in February by a report by Louise Casey which found authorities in the South Yorkshire town were "in denial" about the shortcomings exposed by the Jay Report, prompting ministers to send commissioners in to take direct control of the council.

Prof Jay will be among those attending the Downing Street summit, along with Home Secretary Theresa May, Health Secretary Jeremy Hunt, Justice Secretary Chris Grayling, Education Secretary Nicky Morgan, Communities Secretary Eric Pickles, Rotherham MP Sarah Champion, Commissioner for Rotherham Sir Derek Myers, Children's Commissioner Anne Longfield and Norfolk Chief Constable Simon Bailey, who leads for the Association of Chief Police Officers on child protection issues.

Also present will be representatives of local authorities in areas including Rochdale, Nottingham, Kent, Middlesbrough and Barking & Dagenham.

The discuss will consider a new package designed to ensure local areas have long-term practical plans to uncover child sexual exploitation and bring more offenders to justice, or face tough consequences.

The plans aim to "eradicate the culture of denial" with new joint official health, police and education inspections and a new Child Sexual Abuse Taskforce of experts in social work, law enforcement and health to support local areas.

The Department of Health has also published new guidance on the role of school nursing services in preventing child sexual exploitation and the Department for Education will announce the allocation of £3.8 million of funds under its Innovation Programme to child protection projects in Sheffield, South Yorkshire, Wigan, Rochdale, London and Durham.

Proposals for a crime of "wilful neglect" of children will be considered as part of a planned consultation on mandatory reporting of child abuse. The sanction would be introduced as an extension of the crime of wilful neglect of patients by care workers in this year's Criminal Justice and Courts Act.

David Simmonds, chairman of the Local Government Association's children and young people board, said: "Councils have been leading the way in tackling child sexual exploitation and serious case reviews have highlighted the important difference this work has made since 2011 in protecting some of our most vulnerable children.

"But we cannot tackle this damaging crime alone; such abuse needs to be taken seriously on a national level.

"There is no question that those who are responsible for failing vulnerable children should be held to account, whether they are social workers, teachers, or local or national politicians, but we need to move on from the muddled situation councils currently face so the detail of today's proposals is important to get right.

"The LGA has long called for multi-agency inspections to examine every organisation involved in child protection. Councils are committed to working with the police, health workers and schools and we need an inspection process that mirrors this so no one falls through the cracks. Far too many times social workers hear of abuse too late, when we need to be intervening earlier."

Shadow home secretary Yvette Cooper said: "We all agree we need a stronger child protection system that properly listens to children. The Prime Minister has a real opportunity to improve child protection. But these changes don't yet go far enough to deal with the serious problems in the system.

"Stronger laws are needed to protect children. The Government should bring forward a legal duty to report child abuse, a new specific offence of child exploitation and new child abduction warning notices - however the Government voted against those last week.

"And most important of all, we desperately need proper, compulsory sex and relationship education in schools to teach young people about consent and healthy relationships - however the Government is continuing to refuse to bring it in.

"Support for victims is vital, but the delays in child and adolescent mental health services remain too long."

Anne Longfield, the Children's Commissioner for England, told BBC Breakfast: "The Children's Commissioner Office has looked into (this type of abuse) and reported very worrying levels of this happening around the country so the summit today is something that we've wanted to see for a while, we've wanted to see this in place, and the potential to make a difference here is one that is very, very urgent.

"I think this is a very clear and symbolic signal that things need to change. We can't have this situation where children suffering one of the most horrendous crimes you can think of, as young as 11 or 12, are being systematically ignored if they present to you. The firm message here is that professionals must respond."