Theresa May has attacked the lack of black and minority ethnic officers and women in the police service, describing the situation at some forces as "simply not good enough".
In a speech to members of the National Black Police Association (NBPA), the Home Secretary said "diversity profiles" covering England and Wales showed no force has a black and minority ethnic representation reflecting its local population, while four forces have no black officers.
Mrs May told the association's annual conference in Birmingham: "These profiles, based on self-declared ethnicity data supplied by forces, give breakdowns for officers in each force by gender and ethnicity, compared against the local population.
"They reveal a hard truth - that no force has BME representation that matches its local demographic.
"Incredibly, this data shows that four forces do not employ any black, or black British, police officers at all, and female officers make up 28% of all police officers but 51% of the total population.
"This comes on top of existing statistics showing that there are only two chief officers who self-identify as BME in England and Wales, and 11 forces with no BME officers above even the rank of chief inspector."
The Home Secretary said she hoped the figures would act as a "wake-up call" to forces and provide chief constables with the information they need to identify areas for improvement, as well as for elected police and crime commissioners to hold them to account.
Data submitted to the Home Office, which are based on information officers declare themselves, suggest that as at March 31 the four forces with no black officers are Cheshire, Durham, North Yorkshire and Dyfed-Powys.
However, responding to Mrs May's speech Durham Police and Crime Commissioner Ron Hogg said it was "factually incorrect to say we have no black officers". Dyfed-Powys also said it has black officers.
Meanwhile, Metropolitan Police assistant commissioner Helen King disputed figures about the career prospects of black and minority ethnic officers.
On progression to senior ranks, she told BBC Radio 4's World At One: "I think the figures that have been quoted nationally today are wrong, in that I know within London I work with at least four chief officer colleagues who are from black and minority ethnic backgrounds."
The Equality and Human Rights Commission welcomed Mrs May's challenge, saying: "Britain is a diverse society and in order for the public to have full confidence in policing they need to see a service which is inclusive of all parts of the community."
The Home Secretary's address also led to renewed scrutiny of the possibility of fresh budget cuts for forces.
Shadow police minister Jack Dromey said: "It is right that the police must look like the people they serve if they are to gain the trust and support of communities.
"However, many forces in the UK have already said that under the severe cuts proposed by the Tories they will not be able to recruit until 2019 at the earliest.
"The police must act, but it is extremely difficult for forces to improve diversity and to carry on protecting communities whilst the Tories continue on their mission to slash police funding and hollow out the police service."
During her speech, the first by a Home Secretary to the NBPA's conference since 2003, Mrs May also slapped down Britain's most senior police officer in a row over the use of stop and search powers.
Claims that knife crime is rising as a result of curbs on the policing method are "simply not true", she said.
The comments put her publicly at loggerheads with Metropolitan Police commissioner Sir Bernard Hogan-Howe, who suggested earlier this year that an increase in knife offences in London could be connected to reductions in stop and searches.
Her remarks drew a combative response from Scotland Yard, which accused the Home Office of "misunderstanding" its response to recent rises in knife crime and "our future intentions".