A financial crime unit is to be launched in Peterborough to stop drug dealers in prisons making money.
Justice Secretary David Gauke will warn kingpins their cash will be tracked down and seized by the HM Prison and Probation Service team.
But he will also set out plans to boost prisoner rehabilitation and funding to help educate young offenders.
Mr Gauke will tell the Conservative Party conference: “My message to kingpins is this: we are already blocking your phones, putting you in isolation and now we will make sure you can’t access your money.
“Dealing drugs in prison will no longer be profitable because we will find your assets and we will seize them.”
The new financial crime unit, which will be based in Peterborough, will probe how bank accounts are being used to pay for drugs in prison and track down the criminals linked to them.
It will have the power to close accounts and freeze assets as well as make arrests.
Meanwhile, more prisoners will be given training to help them get into work once they are released and £5 million will be put into creating the first secure school to improve the education of young offenders, Mr Gauke will say.
“Getting prisoners rehabilitated will reduce crime and ensure there are fewer victims of crime in future. It will also cut the £15 billion cost that reoffending has on society.
“We know that offenders are far less likely to reoffend if they have a job. That is why I launched the Education and Employment strategy, which will expand opportunities for offenders to get education and skills training, and work experience so they can get a job when they get out.”