A controversial report on race has described Seamus Heaney as a "Commonwealth" writer "steeped in British cultural traditions".
The review by the Commission on Race and Ethnic Disparities, ordered by the British government and published last week, has been strongly criticised for finding that the UK "no longer" had a system rigged against minorities.
Equality campaigners said it downplayed the extent of racism in British society and its institutions.
Prime Minister Boris Johnson's senior adviser on ethnic minorities, Samuel Kasumu, is to stand down amid the row.
There has also been criticism of a description of Seamus Heaney, a Nobel Laureate from Co Derry, as a "Commonwealth" writer.
In a section on education, it stated: "The language of writers in the Commonwealth, such as Derek Walcott, Seamus Heaney, and Andrea Levy, is steeped in British cultural traditions, but these writers have also shaped contemporary thinking and attitudes.
"Learning about the way cultures change over time, and how other writers have drawn inspiration from outside their immediate country, can help young people appreciate the past, and see themselves in it, rather than reject it as exclusionary."
Heaney, who was born into a rural Catholic family in Bellaghy, died in 2013.
He famously once wrote: "Be advised, my passport's green / No glass of ours was ever raised / To toast the Queen."
Writer and former BBC broadcaster Gavin Esler, who began his journalism career in Northern Ireland, criticised the report.
"If you asked Seamus Heaney he would say he was Irish," he tweeted.
"If you read his poetry, it is the poetry of an Irishman. If the UK race report believes Seamus was a 'writer in the Commonwealth' then whoever wrote that race report really hasn’t a clue."
Irish academic Brigid Laffan also tweeted: "Seamus Heaney was not a writer of the Commonwealth - he was first & foremost himself & then an Irish writer. He was not steeped in British cultural traditions - get a grip & stop appropriating the cultures of those Britain 'others' by reflex."
The criticism follows a row over the use of an image of Heaney by the British government as part of branding for plans to mark the centenary of Northern Ireland.
It emerged that the writer's family was not asked permission for a colour portrait to be used among images in the ‘Our Story in the Making: NI Beyond 100’ initiative.
SDLP leader Colum Eastwood described it as a "cynical attempt to co-opt Seamus Heaney’s image and reduce his work to a branding tool to promote that narrative about partition".
