Rogue gardaí colluded with the IRA through the Troubles, even helping to prevent its entire army council from being arrested during a critical temporary ceasefire, a former director of intelligence for the republican movement has claimed.

IRA leaders received a tip-off from high up within the Garda Síochána that the force’s Special Branch was about to arrest its ruling command while it was at a secret location for talks with Protestant clergymen in 1974.

Kieran Conway, the head of the IRA’s intelligence gathering department for a period in the 1970s, also alleges in a new book that members of the Dublin establishment including a top banker, stockbroker, a leading journalist and several mainstream politicians aided the Provisionals in their armed campaign.

Elite figures in Irish society ferried IRA weapons around in top-of-the-range cars and hid wanted activists in houses in affluent areas of Dublin such as Killiney, according to Conway.

Conway’s allegations are bound to bolster consistent unionist claims that sections of the Irish social and political establishment gave logistical support and cover to the IRA during the Troubles and will fuel unionist demands that any over-arching inquiry into the Troubles should be held on both sides of the border.

The ex-IRA intelligence officer turned Dublin barrister told the Guardian newspaper that the Feakle talks in December 1974 not only repaired the organisation’s image after the Birmingham and Guildford pub bombings that year but also enabled the Provisionals to re-organise during a brief ceasefire.

To mark the publication of his memoir South Side Provisional, Conway also claimed that the entire IRA leadership was almost captured during the secret talks in Co Clare with Protestant ministers that led to a ceasefire which lasted into mid January 1975.

“I think that the army council had particular contacts with those in the security area which weren’t even shared with me. We had contacts in the law offices of the State and contacts in the upper echelons of the guards. Take something like Feakle; the place was raided and they (the leadership) got away. Because a tip-off was received that the Special Branch were on their way to Feakle and that tip-off came from within the Garda,” he said.

Asked if this was just a one-off example of individual gardaí colluding with the IRA, Conway said: “It wasn’t just in 1974 and it wasn’t just concentrated in border areas like Dundalk, it was some individuals but it was more widespread.”

Pressed on whether any members of the Irish parliament during the Troubles, and before Sinn Féin’s entry into it, helped the provisional IRA cause, Conway responded: “I really would not want to say. Wild horses wouldn’t drag me to the names of any of those in the establishment who helped us. But there were those who definitely colluded with us.”

He said that as well as moving guns around for the Provisionals, leading figures in Dublin’s elite also shifted money about for the IRA.

On the Birmingham pub bombings, the 40th anniversary of which fell this November, Conway described them as a “total disaster” and said the IRA unit responsible could not find a functioning telephone box to issue a warning in time to clear the bars in the city’s Bullring that could have prevented the mass loss of life.

For decades the IRA never publicly admitted they carried out the atrocity but Conway said not only did the organisation bomb Birmingham but they knew in Dublin that the six Irishmen arrested over the explosions were innocent “from the get go, from the very start”.

In his time as a Provisional IRA recruit in 1970, having been radicalised during the 1968 student protest movements, Conway met with senior republicans including the future deputy first minister of Northern Ireland, Martin McGuinness, and the Sinn Féin president, Gerry Adams.

By 1974, with Conway now heading up the IRA’s intelligence department, the Provisionals killed 140 people including 21 British civilians blown up in the Birmingham pub bombings. Three years earlier he had been arrested in Derry after an army raid on an IRA safe-house. Conway was later jailed in Belfast’s Crumlin Road prison and went on hunger strike to achieve political status.

Although he left the IRA in 1975, Conway later rejoined the organisation during the 1981 hunger strike. He finally broke with the republican movement for good in October 1993 when the British and Irish governments announced the Downing Street Declaration. Conway said the communiqué basically re-enforced partition and allowed the unionist population to continue to veto any constitutional change on the island of Ireland.

“The outcome was one of disappointment as it was not what we fought for. The IRA went on ceasefire, it decommissioned and did all the things they said they would never do and disappeared into history. It was a complete and utter defeat, absolutely.”

Conway added however that the current armed republican dissident campaigns are “utterly futile”.

His book tracks his journey from a privileged upper-middle-class upbringing in south Dublin to rioting on the streets of Belfast in 1970 and later that year joining the IRA as an intelligence officer helping to organise bank robberies in London. Southside Provisional: From Freedom Fighter to The Four Courts is published by Orpen press Guardian News and Media