An application to quash the original Hillsborough inquest verdicts has been made by Attorney General Dominic Grieve.
Families of the victims have campaigned for years to have the original 1991 accidental death verdicts overturned.
Mr Grieve, the government's most senior law officer, made the application to the High Court, paving the way for new hearings.
He said the main basis for the move was new medical evidence.
He explained that the alteration of evidence by the police and other emergency services was also a supporting factor, along with stadium safety.
"I believe that the case for the High Court to quash the original inquests is a good one," Mr Grieve said.
"My application has now been lodged with the court. It is my intention to appear to argue the case at the hearing that will take place in the High Court.
He said the views of the families had been sought before filing the application, with the coroners for South Yorkshire and West Yorkshire also contacted.
A date for the High Court hearing has yet to be fixed.
Ninety-six Liverpool supporters died as a result of the crush on 15 April 1989 at Sheffield Wednesday's Hillsborough stadium, where their team were to meet Nottingham Forest in an FA Cup semi-final.
The move comes after a recent damning report into the way the disaster was handled.
Anne Williams, whose son Kevin died in the disaster, wrote on Twitter: "Just received e mail the Attorney General is sending Kevin's case to the divisional courts seeking a new inquest (into) his death."
More than 100,000 people have signed an e-petition calling for a fresh inquest into Kevin Williams' death to be held swiftly as his mother is suffering from cancer.
Mr Grieve announced in October he would make an application to the High Court.
Margaret Aspinall, whose son James, 18, died at Hillsborough, said: "We have waited over 20 years for these verdicts to be overturned and I'm sure all the families will be delighted to hear that these steps are being taken.
"It is a great step towards getting the justice we have fought for."
A report by the Hillsborough Independent Panel in September revealed police and emergency services had made "strenuous attempts" to deflect the blame for the disaster on to fans.
It also found 164 police statements had been altered - 116 of them to remove or change negative comments about the policing of the match.
The report said 41 of the 96 who had died had had the "potential to survive".