The group, joined in the Plantagenet Alliance, a sort of Ricardian boosters club, plan to file a legal challenge to the Ministry of Justice, The Guardian reported. The ministry gave the University of Leicester a license to excavate for Richard's body, which was found under a Leicester car park and identified through a DNA comparison with a remote descendent of Richard's sister, Anne of York.
Richard was given an unceremonious burial at a Leicester church after he was killed in the Battle of Bosworth Field in 1485. The government takes the position that the decision on his reburial is up to the university, and Queen Elizabeth II, a descendent of Richard's brother, King Edward IV, has remained silent.
The Richard III Society, a group that has been trying for decades to repair his reputation, backs Leicester Cathedral and has submitted a proposed design for a tomb.
The Plantagenet Alliance argues Richard had longstanding ties with York and the surrounding region as son of Richard, duke of York, and as his brother's chief lieutenant in the north and lord of Middleham Castle.
A spokesman for the university said "good archaeological practice" calls for reburial in a place near the longtime burial spot.
"Richard III is believed to have no living descendants. Any distant relations are therefore descended from his siblings," the spokesman said. "Statistically speaking, many tens of thousands of individuals alive today are descended in this way. There is no obligation to consult living relatives where remains are older than 100 years."