Police will have to abide by a new code of ethics similar to the hippocratic oath taken by doctors, the Home Secretary has said.
Theresa May told a College of Policing conference it was "astonishing" that the guidelines were not already in place, and that a national register of officers who have been sacked from the service will also be set up for the first time.
Mrs May said: "It's astonishing that the police have not had an explicit code of ethics, an equivalent if you like to the hippocratic oath for doctors.
"I think it will prove vital for establishing and maintaining fundamental ethical standards for police officers."
The College of Policing launched a consultation on the new code today, and it is expected to be published in the spring.
Mrs May's comments follow a series of events that have shaken confidence in the police, including the renewed inquiries into the Hillsborough disaster, revelations about undercover officers and rows surrounding "Plebgate".
She said that plans to expand the powers of watchdog the Independent Police Complaints Commission (IPCC), first announced in February, are on track and that it will take on additional cases next year.
The proposals were outlined as the watchdog took on a new investigation into the aftermath of the Hillsborough disaster, the biggest ever probe into police misconduct in the UK.
The Home Secretary said: " I know that some forces and PCCs (police and crime commissioners) are resisting the transfer of resources necessary for the IPCC to take on this bigger role, but I want to say very clearly that the events of last year prove overwhelmingly the case for a beefed up IPCC, and that's what I'm determined to deliver."
The five-week consultation on a draft version of the code, which will ultimately apply to all police officers and staff, runs until November 29.
Yesterday MPs grilled three police officers caught up in a row over a meeting with former chief whip Andrew Mitchell in October last year, following the "Plebgate" incident.
Police Federation representatives inspector Ken MacKaill, detective sergeant Stuart Hinton and sergeant Chris Jones initially claimed that Mr Mitchell had refused to tell them what he said during a foul-mouthed rant at officers in Downing Street the previous month.
But they were later accused of giving misleading statements and could now face disciplinary action.
Mrs May added: "Where the IPCC has needed new powers, for instance in its investigation of Hillsborough, we have legislated to provide them, and if the evidence of the past week shows we need to go further, we will do so."
Keith Vaz, chairman of the Home Affairs Select Committee which questioned the three officers during a mammoth evidence session yesterday, said: "We need a new contract between the police and the public, as was evident at the select committee session yesterday into the Andrew Mitchell affair.
"I am delighted that the Home Secretary has accepted the committee's recommendations and welcome a 'hippocratic oath' for Britain's police force.
"We will have a professional body on par with the other great professions which is where we want policing to be."
But shadow home secretary Yvette Cooper claimed that the changes are not sweeping enough.
"Today's plan from the Home Secretary goes nowhere near far enough on police standards," she said.
"A code of ethics is of course right, but it's not enough. This week's evidence at the Select Committee should show everyone we need an entirely new framework for standards, and a better system for when things go wrong.
"The IPCC doesn't have the power, authority or resources to investigate and hold the police to account. It should be replaced with a much stronger, properly empowered and better-equipped Police Standards Authority.
"Simply giving the IPCC more resources isn't enough - it will just expand a structure that isn't working, isn't proactive enough and has failed to deliver for victims, the police or the public too many times."