David Hart, a right-wing political activist and adviser to MacGregor, the NCB, and Prime Minister Margaret Thatcher, claimed that Orgreave was "a set-up by us". He said in a 1993 interview, "The coke was of no interest whatsoever. We didn't need it. It was a battleground of our choosing on grounds of our choosing. I don't think that Scargill believes that even today. The fact is that it was a set-up and it worked brilliantly." Following his comments, senior managers from the NCB denied these claims and threatened Hart with disassociation. John Alderson, in "Principled Policing: Protecting the Public with Integrity" (1998), wrote that if MacGregor and Hart's claims were true, the "conspiracy to draw the miners into mass pickets and predictable violent conflict between the police and themselves" constituted a "deceit... tantamount to incitement".