The bones of Richard III should be reburied under a modest slab in the floor of Leicester Cathedral, “a place of dignified simplicity” rather than a grandiose modern reinvention of a medieval tomb, the cathedral authorities have decided – in a move that will do nothing to resolve the debate over where and how the king should finally be buried.

The cathedral is only 100 yards from the car park where the remains were excavated last year, and identified as those of the last Plantagenet king at a press conference last month that made headlines across the world.

The decision was greeted with some dismay by the Richard III Society, which mainly funded the excavation and has been raising funds for a more elaborate limestone sarcophagus. “It is up to the cathedral, they have their own rights – but we would of course like to see a decent tomb rather than a slab in the floor,” Richard van Allen said.

As other sites including York continue to vie for the honour of providing Richard with a last resting place, the Leicester cathedral authorities are quietly confident that their St Martin’s, a medieval parish church that became a cathedral in the 20th century, will prove the permanent sanctuary for his bones.

They have issued a design brief for the memorial, which is likely to resemble the existing tribute stone near the high altar, installed in the 1980s when the site of his grave had been lost for centuries.

The cathedral is inviting applications from architects in Britain or internationally, but after a meeting on Tuesday of the cathedral chapter, it is clear they envisage something far more modest than surviving medieval tombs in cathedrals such as Westminster.

The wrangle highlights the rift between supporters and critics of Richard, whose character is still debated. He was a noble leader traduced by Tudor propagandists in the view of the Richard III society, but to others he was a murderer responsible for the death of the nephews in his care, the Little Princes in the Tower.

According to the design brief: “They will be reluctant to site a large memorial in the cathedral which would assume disproportionate significance in a modest building and cannot easily be located in any position in which it would not restrict the capacity of the building on major occasions.

“While the remains of an English king are of historical significance – and experience from the royal visit for the diamond jubilee demonstrated how people are attracted to the mystery of royalty – it should not be forgotten that Richard demonstrated both the honourable and dishonourable characteristics of human beings.

“Opportunities for prayer and reflection should focus on themes of sin and redemption, justice and peace, as reflected in our history and our present.”

Richard III was killed during the battle of Bosworth in August 1485. He was the last English monarch to die in battle.

• This article was amended on 14 March 2013. It originally stated that Richard III was the last monarch to die on a battlefield in England. In fact that “honour” belongs to James IV of Scotland, who was killed in the battle of Flodden in 1513. Richard III was the last English monarch to die in battle. This has been corrected.