Home Secretary Amber Rudd has rejected calls for a statutory inquiry or independent review into the clash between police and miners at Orgreave.
Here's everything you need to know about the violent clash all those years ago.
What was the so-called Battle of Orgreave?
It was the fiercest clash between police and the picket lines during the 1984-85 miners' strike.
Violence erupted between the two groups on June 18 1984 as thousands of protesters at the South Yorkshire colliery were met by police clad in riot gear and wielding truncheons.
What actually happened?
Almost 5,000 officers formed a solid barrier against the miners, who had gathered at the works near Rotherham to stop coke deliveries leaving for steelworks in Scunthorpe.
The police, some on horseback, made regular charges to break up the crowds, often under a hail of stones and missiles.
How many people were hurt?
Official reports said 30 officers and 50 pickets were hurt, including National Union of Mineworkers president Arthur Scargill, but many others are believed not to have reported their injuries.
Was anyone arrested?
Many miners were arrested following the so-called battle, but were cleared after a court case against them was thrown out.
What did people think of the way the police acted?
The number of police involved and the tactics used during the clash were unprecedented.
Images of the violent confrontation shocked many, fuelling criticism of the police role and leading to accusations that the miners had been "set up".
Campaigners also allege the police manufactured statements following the incident to discredit those involved.
Why did Amber Rudd decide not to set up an inquiry?
Rudd said she made the "difficult decision" because "ultimately there were no deaths or wrongful convictions" resulting from the violent encounter in 1984.
How have people reacted to her decision?
Rudd's decision has been met with disappointment from MPs, the general public and the Orgreave Truth And Justice Campaign - which was calling for a full public inquiry into South Yorkshire Police's conduct during the clashes.
People have been expressing their shock and outrage at the Government on Twitter.