Campaigners are stepping up calls for the Government to set up a public inquiry into policing of the miners' strike 34 years ago.
Members of the Orgreave Trust and Justice Campaign (OTJC) will hand in a letter to the Home Office in London on Wednesday pressing for action.
It will be the second anniversary of a decision by former Home Secretary Amber Rudd against holding an inquiry into events at Orgreave in South Yorkshire in June 1984.
In what became known as the Battle of Orgreave, 95 mineworkers were arrested, although never convicted, and a number were injured after clashes with the police.
Campaigners claim police officers violently attacked mineworkers taking part in a demonstration outside a coking plant at Orgreave.
Kate Flannery, secretary of the OTJC, said: "When Amber Rudd resigned in relation to the Windrush scandal we expected her successor Sajid Javid to review our call for a public inquiry, but we're still waiting for a response."
She said that some documents that had been released highlighted "active Government involvement" in the miners' strike, adding: "Many other papers aren't due to be made public until as late as 2066.
"That's why it's vital that we have an inquiry to ensure we have a thorough and authoritative review, and to be able to access everything relevant."
Former mineworker Kevin Horne, one of those arrested at Orgreave, said the Government was "frightened to unearth the truth", adding: "It's a disgrace. What are they hiding, and why are they covering up the corruption of the past? This issue won't go away."