Adrian Mitchell, the playwright, poet and children’s author known as the Shadow Poet Laureate, has died at the age of 76.

Mitchell was known for a forthright voice often laced with tenderness and wry satire, and the social conscience of his poems dealt with nuclear war, Vietnam, prisons and racism, leading the socialist magazine Red Pepper to dub him “Shadow Poet Laureate” in 2002.

The understated power of his poems, combined with playfulness, became a part of the folklore of the Left, and his work was often read and sung at demonstrations and rallies.

Mitchell had been suffering from pneumonia for two months, and died from a suspected heart attack on Saturday night, just two days after writing his last poem, entitled My Literary Career So Far – intended as a Christmas gift to “all the friends, family and animals he loved”.

Born near Hampstead Heath in North London in 1932, Mitchell wrote his first play at the age of nine while at Greenways school in Wiltshire. The Animal Brains Trust, in which he played a kangaroo, manifested his love of animals. After leaving school, Mitchell was conscripted into the RAF which, he said, “confirmed my natural pacifism”.

Mitchell went on to study at Christ Church College, Oxford, where he was taught by J.R.R. Tolkien’s son. After graduating from Oxford, Mitchell went on to be a journalist at the Oxford Mail, and then the Evening Standard.

After writing his first novel and television play, he became a freelance arts reporter for numerous national newspapers until 1966, when a small legacy from his mother allowed him to devote himself fully to writing poems, novels and plays.

Mitchell was perhaps best known for his Vietnam war poem To Whom It May Concern, which was first read in Trafalgar Square in 1964.

His publisher, Bloodaxe Books, said on its website: “His poetry’s simplicity, clarity, passion and humour show his allegiance to a vital, popular tradition embracing William Blake as well as the Border Ballads and the blues.”

Mitchell leaves his wife, the actress Celia Hewitt, and their two grown-up daughters, as well as two sons and a daughter from his first marriage.

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