With no room for Mantel’s conclusion to her Wolf Hall trilogy, the six finalists also include four debuts

• Judging the Booker prize: ‘These books are about living under intense pressure’

Hilary Mantel will not win a third Booker prize with the final novel in her Thomas Cromwell trilogy, after American writers made a near clean sweep of this year’s shortlist.

With four writers of colour among its six authors, the shortlist, announced on Tuesday, is the most diverse line-up in the prize’s history. Four debut novelists – Diane Cook, Avni Doshi, Douglas Stuart and Brandon Taylor – are up against the acclaimed Zimbabwean Tsitsi Dangarembga, and the Ethiopian-American Maaza Mengiste for the £50,000 award.