Police officers responsible for protecting children, the elderly and domestic abuse victims should require a licence to carry out the role, ministers will be told this week.
The head of the body that represents senior operational police leaders will argue that personnel in charge of keeping the most vulnerable people in society safe should have training and development to an agreed national standard.
Chief Superintendent Gavin Thomas, President of the Police Superintendents' Association of England and Wales, will describe vulnerability as "one of the new volume demands that will define our service and what do we for years to come".
He will tell the Association's annual conference on Tuesday: "We have standards, accreditation and skills to practice in firearms, public order and driving patrol cars.
"But currently there is no such requirement for protecting children and vulnerable people.
"Superintendents are carrying significant amounts of responsibility and must have the training and development to do their jobs effectively.
"It is a highly skilled specialism and should require a licence to practice."
Earlier this year the Association carried out a survey of public protection leaders in forces in England and Wales.
It found nearly half of the respondents reported they had no previous experience of public protection - while 82% had received no training or development in public protection before their appointment.
Mr Thomas will call for a common definition of vulnerable to be applied across public services.
He will say: "There is no standard definition that all public services are working to.
"It cannot be right that a missing person in one area might not be defined as a missing person in another area."
He will also suggest a review of "multi-agency safeguarding hub" (MASH) models.
The officer will say: "The MASH should be at the centre of partnerships, working together to protect the most vulnerable in our society.
"Yet across England and Wales they are very different in how they are organized, operate and share what is absolutely critical."
Last year a watchdog report on how effectively forces in England and Wales protect vulnerable people from harm and support victims rated four services as inadequate while another 27 had shortcomings in at least one of the areas assessed.
A Home Office spokesman said: "Proposals are already being brought forward which will see minimum training and standards for specialist roles, including those who work with victims of domestic abuse and child sexual exploitation.
"The College of Policing will be given the responsibility to enforce these standards through a system of national accreditation. This has already been a proven success in other critical areas such as firearms and public order.
"Police reform is working and we must ensure victims have the confidence that the police will take these crimes seriously, and be properly equipped to deal with victims."