Corbyn's campaign on behalf of Birmingham Six not helpful, wrote ex-SDLP leader Hume
Former SDLP leader John Hume felt Jeremy Corbyn's intervention was "not helpful" to the Birmingham Six.
Irish state papers detail the future Labour leader's campaign to free the Guildford Four and Birmingham Six prisoners.
One is a letter from November 1989, addressed to Dermot Gallagher, of the Anglo Irish Division within the Irish Department of Foreign Affairs, from David Donoghue, press and information officer from the Irish Embassy in London. It details a conversation with Mr Hume.
The letter reads: "On the Birmingham Six case, Hume commented that the involvement of people like Jeremy Corbyn in the B6 Campaign (he was referring to a press conference held by Corbyn and Gerard Conlon yesterday) was not helpful.
"The Birmingham six have no chance of release, he remarked, unless like the G4, they get church leaders and other Establishment figures behind them."
The letter goes on to detail that Mr Hume "remains absolutely certain" John Walker - one of the Birmingham Six - is innocent.
Mr Corbyn, MP for Islington North, campaigned for both groups in Parliament and visited the prisoners, who were wrongfully convicted for IRA terror attacks.
Another letter found in the papers describes a visit to one of the Guildford Four, Paul Hill, in Albany prison in April 1989. Shane O'Neill, third secretary in the Irish Embassy in London, wrote to the Anglo Irish Division that Mr Hill had been comforted by the help of the MP.
Mr Corbyn had raised a parliamentary question in the Commons about Mr Hill's health issues, a saliva gland that needed removed, for which he needed an operation and found it difficult to eat.
The letter reads: "[Mr Hill] said that both Gifford and Jeremy Corbyn said that in the event of an appeal failing there was a strong likelihood that the Home Secretary would grant a pardon within 18 months.
"He is trying to remain calm about the likely outcome of the appeal so that failure will not come as too great a disappointment. At the same time he is so optimistic about the number of people who have weighed in with their support."