Labour police commissioners will prevent any efforts to privatise local police forces, Yvette Cooper promised today.
The pledge will come during a speech which sees the shadow home secretary echo Ed Miliband's 'One Nation' agenda with a land-grab on traditional Tory 'law and order' territory.
"Tory ministers want huge swathes of policing handed over to private companies. Nothing ruled out. Contract tenders which include neighbourhood patrols, detective investigations and more," she said during her keynote speech to conference.
"Pushing forces to sign up to massive contracts with a single organisation where value for money is at risk. Have they learned nothing from the Olympics?"
Labour feels certain the failure of G4S to provide security staff for the Olympic games was a game-changer in the way private sector outsourcing is treated in Westminster.
The shadow home secretary, who is on the right of the Labour party, did accept there was a role for the private sector in some areas, however.
"Policing in the interests of justice not just the corporate balance sheet," she explained.
"That means tough tests must apply on value for money, on resilience and security, on transparency and accountability and, most of all, on public trust.
"Let's be blunt. We don't want private companies patrolling the public streets of Britain. We want police officers and PCSOs policing our communities - not private companies putting them under guard."
Cooper, who forms one half of a power couple with shadow chancellor Ed Balls, will also demand new criminal offences for those found guilty of financial wrongdoing, via an Economic Crime Act.
"People were fiddling figures to get rich, while small businesses paid the price," she said of the Libor scandal.
"Yet no one has been arrested. The experts say it can't even be treated as a crime offence. The police and the SFO (Serious Fraud Office) don't even seem to know where to start.
"In the United States they have seen 800 prosecutions for serious fraud since 2011. Here in the UK the SFO pursued just 20.
"If someone doesn't pay their TV licence they'll end up in court. But defraud millions of pensioners or small businesses and you can get off scot free."
Today is the final full day of the Labour party conference.