Four members of the Balcombe Street siege gang will have their transfers to Ireland considered by the British government "fairly shortly", the British Prison Service said this week.
Under Home Office guidelines a prisoner cannot apply for a transfer unless a tariff - the minimum length of the sentence to be served - has been set.
In the case of the Balcombe Street Gang setting a tariff will allow the men to have their applications for transfer to Ireland considered by the British and Irish governments.
Papers have been sent to the Home Secretary, Mr Jack Straw, and he is understood to be considering setting a tariff in the cases of Eddie Butler, Hugh Doherty, Joe O'Connell and Harry Duggan.
They were sentenced to life in 1975 following a five-day siege at Balcombe Street in London.
They had spent the previous few weeks carrying out bomb attacks in London and during the siege the men kidnapped two people as they attempted to shoot their way out of a building.
A policeman was killed during the siege. In 1977 O'Connell admitted responsibility for the Guildford and Woolwich bombings in 1974 for which the Guildford Four spent 15 years in prison.
The move on tariffs lends weight to recent reports suggesting only one Irish prisoner should be left in England and Wales next year. Sixteen transfer applications are under consideration, nine of which will be finalised before Christmas.
Nicholas Mullen, who was sentenced to 30 years in 1990 for conspiracy to cause explosions in London, has yet to make a formal application for transfer although it is understood the option has not been ruled out.
Pressing the issue of tariffs during her visit to Frankland Prison this week, the Fianna Fail spokesperson on Prisoners, Ms Cecilia Keaveney, gave an assurance to Irish prisoners in Britain that the Government would do "everything in its power" to ensure the amendment to the Transfer of Prisoners Act 1995 is completed in the Dail and Seanad before Christmas.
Referring to the case of John Kinsella, Ms Keaveney said Kinsella was "quite concerned" by the lack of movement by the British judiciary in setting a date for his appeal. Kinsella, who is serving a 16-year sentence for possession of explosives in connection with the Warrington gasworks bombing in 1993, is preparing for a Court of Appeal hearing early next year.