A project to help encourage victims and witnesses to give evidence in court was due to be launched on Wednesday.
The units will try to identify instances of witness intimidation
The new £27m project will introduce witness care units across England and Wales to help people sort out problems preventing their appearance.
Nearly 3,000 crown court cases and 13,000 magistrate hearings were adjourned in 2002 because crucial witnesses failed to turn up.
Pilot schemes have seen a rise in court attendance figures.
The new witness units will be set up to remind people to attend court and to help overcome problems like arranging and finding childcare.
Assessments at the units will also aim to identify instances where witnesses are being intimidated.
The units will also warn witnesses what will be required of them in court and update them on the progress of their case.
The Attorney General, Lord Goldsmith QC, said victims and witnesses had not always received the support they needed and "that must change".
He said: "Giving evidence at court is a daunting experience for anyone. The criminal justice system has a responsibility to ensure victims and witnesses feel safe and able to give evidence.
"Victims and witnesses have a right to expect a smooth and co-ordinated service from the criminal justice agencies. "
He said he hoped the project would put witnesses "at the heart of the criminal justice system".
The No Witness, No Justice campaign is being funded by the government's Invest to Save initiative.
It is being launched jointly by the Crown Prosecution Service and the Association of Chief Police Officers.
The campaign follows an Audit Commission report in December saying the criminal justice system's failure to deliver for many victims was eroding public confidence.
The report called for consistency in the way witnesses and victims are treated.