The details of several encounters are known, but it seems likely that there have been many other contacts which have never emerged into public view. It is certainly the case that contact occurs on a daily basis in contexts such as prisons, interrogation centres and on local council business.
On a more strategic level, however, there have been more important talks between republicans and British representatives. When news of these has emerged, there have been protests from Unionists and Irish governments, both of whom have recurring fears that Britain might do a deal with the IRA.
For example, the former Taoiseach, Garret FitzGerald, described Harold Wilson's action of secretly meeting IRA leaders in Dublin in 1971 as 'an act of treachery'.
Lord Wilson, then Leader of the Opposition, met the IRA again the following year in England, but his aide, Joe Haines, later wrote: 'A meeting of minds was clearly impossible. We were planets apart; words had different meanings . . . it was completely meaningless.'
One of the Provisionals present, Joe Cahill, reached a similar conclusion, describing the Dublin meeting as 'a waffling session. To me it had been a complete waste of bloody time.'
The most direct formal talks between a government and republicans came in 1972 when Lord Whitelaw, then Secretary of State for Northern Ireland, had a group of republican leaders, including Gerry Adams and Martin McGuinness, flown to London for secret talks in Chelsea.
Mr McGuinness recently recalled the occasion: 'We assembled here in Derry, six of us, and we were taken in a blacked-out van from a back road in Shantallow to a field in which a helicopter landed. We were put in the helicopter and brought to the military end of Aldergrove airport near Belfast.
'We were brought then by RAF plane to a military airfield in England, where we were met by a fleet of limousines. They were the fanciest cars I had ever seen in my life: it was a most unreal experience. We were escorted by the Special Branch through London to Cheyne Walk and there we met Willie Whitelaw. We were offered drinks at the meeting and we all refused.'
Mr McGuinness said the meeting was unproductive, he and the others concluding that the British government was not yet at a position where they could do 'serious business'.
Lord Whitelaw was equally disappointed, writing in his memoirs: 'The meeting was a non-event. The IRA leaders simply made impossible demands which I told them the British government would never concede. They were in fact still in a mood of defiance and determination to carry on until their absurd ultimatums were met.'
More systematic contacts took place in 1974 and 1975 when, under a Labour government, senior officials met Sinn Fein leaders on a regular basis at a large house outside Belfast. The meetings helped set up an IRA ceasefire, with the Government designating 'incident centres' designed to provide channels of communication with local republicans.
There have been many more examples of contacts between politicians and paramilitaries or their representatives.
In 1978, Douglas Hurd, now Foreign Secretary, met Gerry Adams when he was a Conservative front bench spokesman on European affairs. He stressed he was acting in his capacity as an individual MP.
In his memoirs, Garret FitzGerald voiced southern Irish fears about the effect of such meetings. He wrote: 'The contacts that had taken place had had the effect merely of prolonging the violence by deluding the IRA into believing that a British government would eventually negotiate a settlement with them.'
Last year a Protestant clergyman recalled a confidential meeting in the 1970s with the late Daithi O Conaill, then leader of the IRA, at which he was trying to arrange a ceasefire.
He said: 'O Conaill told me at the time that we should have one bite at the cherry, no more: 'That's because behind every one of us on the Army Council there's a young man with a gun in his hand who still has to make his name for Ireland and write his name in the history books. And when they take over there will be no more ceasefires.' '
Today Martin McGuinness, 21 years on from his visit to the house in Cheyne Walk, is once again said to be involved in talks with British representatives.
Clearly there have been many precedents for this; but the precedents for success are, equally clearly, unpromising.Reuse content