Campaigners joined a protest in Sheffield aimed at persuading ministers to reverse a decision not to hold a public inquiry into violent clashes between striking miners and police 33 years ago.
A year ago, Home Secretary Amber Rudd ruled out an inquiry into the events at Orgreave in South Yorkshire in June 1984.
Scores of miners were arrested during a day of violence, and many were injured, although all charges were later dropped.
The Orgreave Truth and Justice Campaign held a Halloween protest in Sheffield tonight, including a procession through the city carrying a coffin.
Joe Rollin, the group’s chairman, said plans were still being made for a legal challenge to the Government’s refusal to hold an inquiry.
He said: “Theresa May’s rhetoric about tackling burning injustices was clearly ignored by Amber Rudd.
“For this Conservative Government it is establishment business as usual. For many the wounds of Orgreave are as fresh as if it was yesterday.”
Former miner Kevin Horne, one of those arrested at Orgreave, said: “Orgreave was a seismic event in our history. You have to wonder what the Government is so afraid of in revealing the truth.
“The outcome will be unpleasant but the continuation of deception and a flawed picture is an even uglier threat to the future of justice in Britain.”
The clashes between thousands of police and pickets on June 18, 1984 became known as the Battle of Orgreave.
A British Steel coking plant near Rotherham had been picketed peacefully for weeks, as had many pits which largely came to a standstill because of the strike over jobs and closures by the National Union of Mineworkers.
Protesters blame the then government for being behind the police tactics to break the NUM’s morale but also believe officers went too far.