The 82-year-old cleric, who has spent his life working in remoteparishes, remains almost unknown to the public because of his obsessive privacy and dislike of people. His candidacy is being supported by Lord Gowrie, chairman of the Arts Council of England, Tony Bianchi, literature director of the Arts Council of Wales, and Kevin Thomas, director of the prestigious Welsh Academy.
Lord Gowrie said: "He has a forbidding exterior, but it is extraordinary how simple and communicable his poems are. At first sight they seem almost naive. Then you look again and you see the skill and timing and rhythms of the writing. I'm thrilled to be associated with the campaign to get him nominated."
Nominations for the pounds 630,000 prize, are restricted to writers' groups, professors of English, bodies such as the Arts Council, or past Nobel winners. Thomas's will be made by the Welsh Academy with the support of last year's winner, Kenzaburo Oe, who was bowled over by Thomas's writing.
Thomas is thought to stand a good chance of winning. If he does win, he will be the least well-known author writing in English to have done so.
Thomas is an ardent Welsh nationalist who learnt to speak Welsh - English is his first language - although he has never managed to write in it. His poetry is based on his religious faith, but he does not shrink from portraying his parishioners as sullen, miserly and mean-spirited, and faith in God as often absent.
He refused initially to agree to be nominated before yielding grudgingly on condition that if he won he could make his acceptance speech in his beloved Welsh.
"He is very lukewarm about it," admits Mr Thomas of the Welsh Academy. "I was sitting three rows behind him when somebody first told him what we were doing and he was shaking his head violently. When it was next mentioned, he agreed as long as he could make his acceptance speech in Welsh. It was impossible to say whether he was joking or not because he's so sphinx-like."
Last week the poet was a little more forthcoming. "I don't know anything about the mechanics of the business, but one can only be grateful if anybody thinks you're worth putting up," he said. "It's sort of local boy made good and I imagine that all over the world there are minorities putting up their champions."
In a rare interview with the Independent on Sunday last year, he described his poetry as merely "all right" and said it was "quite immaterial" to him whether he was remembered after his death. "My ambition has been to make poetry out of experience - mine has been particularly narrow."
This month, his latest collection of poems, No Truce with the Furies, is published by Bloodaxe Books. Philip Gwyn Jones, who recently commissioned Justin Wintle to write a biography of Thomas for HarperCollins, said: "He's an unpredictable man."