The casting has been condemned by the actors’ union Equity and drawn criticism from Arts Council England and diversity campaigners who are angry at what they describe as a “whitewashing” of history. Malcolm Sinclair, the president of Equity, said: “Whilst wishing every individual actor in the production well, can it be acceptable best practice in 2015 to cast a project such as this with 22 actors but not one actor of colour or who apparently identifies themselves as having a disability?”

And in a statement, Equity’s minority ethnic members committee said: “To present this benchmark of British heritage in a way that effectively locks minorities out of the cultural picture [literally] flies in the face of the huge conversation taking place in British media at present, of the very real progress made in recent years to increase diversity in our industry.”

Responding to the criticisms, Sir Trevor told The Independent on Sunday said he was a longstanding member of the movement to “cast, whenever possible, according to the principle of diversity”, but in this case of The War of The Roses he had made an “artistic decision” to cast according to “historical verisimilitude”.

He added: “The connections between the characters, and hence the narrative of the plays, are extremely complex, and so everything possible must be done to clarify for an audience who is related by birth to whom. Hence, I decided that, in this instance, these considerations should take precedence over my usual diversity inclination.”

That explanation was confirmed by a spokesperson for the Rose Theatre, who said: “A creative decision was taken by the director that a naturalistic historical approach in casting was required.”

Critics have questioned the “verisimilitude” of the production, which amalgamates Shakespeare’s Henry VI trilogy and Richard III and is sponsored by Norway’s largest financial services group, DNB. Norwegian actor Kare Conradi was chosen to plays Edward IV. And two British actresses, Joely Richardson and Imogen Daines, play the French characters Margaret of Anjou and Joan of Arc.

Simon Mellor, executive director of arts and culture, Arts Council England said: “This production seems out of step with most of British theatre where casting that ignores an actor’s race is increasingly the norm.”

He added: “Whilst we do not fund the Rose Theatre, we expect organisations we fund to actively ensure their programme, and the artists that create it, reflect the people of contemporary England.”

And actor Danny Lee Wynter, founder of Act For Change, which campaigns for greater diversity in the arts, said: “The Wars of the Roses caused us concerns, particularly the justification of historical accuracy which displayed a lack of awareness of the debate … It’s very hard in this day and age to have a company that size which is all white.” Mr Wynter added: He added: “They have not been ‘historically accurate’ in having a Norwegian actor in the company.

Trevor Nunn, the Rose Theatre Kingston, and Ginny Schiller who cast this production have placed themselves in a tremendously unfavourable corner … worryingly, some will take the Rose Theatre’s whitewashing of history as gospel.”

Ms Schiller, who cast the play, told The Independent on Sunday: “On this occasion Trevor Nunn – a director with a proven commitment to diverse casting – decided that because of the complex family tree and conflicting claims to the throne through direct lineage to Edward III, a naturalistic ‘colour aware’ approach was required.” She added: “All the supporting actors will play many parts, and at some point in the trilogy take on roles who are related to the Houses of York and Lancaster by blood. This is why even those roles with no genealogical link to the families were also cast white.”

In a statement last night, Sir Trevor said: “Having been involved since the early 1970s in the movement to cast, wherever possible, according to the principle of diversity, I am, of course, saddened to discover that Equity has criticised the casting for my current project.” He added: “I took the artistic decision that a trilogy of Shakespeare’s early history plays, telling in documentary detail the story of the English monarchy and English nobility in the second half of the 15th century, should be presented with, as far as possible, historical verisimilitude.”

The row highlights the continuing debate over the lack of diversity in British theatre and comes just months after actor Adrian Lester, speaking during an event at London’s National Theatre, said: “It’s up to us to gather in groups and embarrass the sides of the industry that we can…and to consistently, always, constantly ask for change.”

Diversity is one of the biggest challenges facing the arts today, says Equity, and the union recently issued its first ever policy on ‘inclusive casting’ to tackle what is calls “discrimination across the industry.” This calls for targets for casting actors from diverse backgrounds, regardless of sex, disability, race or sexuality, along with equality monitoring of performers, stage management and creative teams.