The typed letter, signed by Gandhi and written from the Aga Khan Palace in Pune during his detention by the British forces, is expected to fetch between £10,000-15,000 when it goes under the hammer at Ludlow in the county of Shropshire on February 14.
In the letter, Gandhi made a reasoned plea to the British authorities for his and his followers' release.
Experts have described it as 'an incredibly important document in world history' because it also signifies Gandhi's final emergence as the one man who could achieve the long awaited independence for India, a media report said.
Richard Westwood-Brookes from Mullock's Auctioneers, who are handling the sale, said the letter is being sold by a man in India who was a freedom fighter with Gandhi.
“Letters of Gandhi are highly sought after around the world but this is without question one of the most significant letters. The letters that have appeared in recent years were saying things like 'thank you for my birthday present',” he said
“But this one is highly significant because it's written from prison. It signifies the moment he was taking on the whole leadership of non-violent moment,” he added.
The letter also refers to the resolution of the All-India Congress held on August 8, 1942, and Gandhi's aim to achieve independence.
“This letter, couched in coded diplomatic terms, signifies Gandhi's desire to achieve a diplomatic strategical struggle for independence, and eventual successful establishment of the State of India,” according to the description of the lot by the auctioneers, who were also behind the last year sale of a collection of material related to Gandhi, including his glasses and prayer book.
Gandhi wrote the letter while he was detained at the Aga Khan Palace in Pune for endorsing the Quit India Movement.