Historic documents released by the National Archives in London have revealed that the British government was sceptical about Bertie Ahern becoming taoiseach after the 1997 general election.
Other files released also show worry among British officials about the 1994 IRA ceasefire, with senior figures concerned that the terrorist group “benefited from the ceasefire”.
The documents, reported in The Irish Times, exposed the concern among senior British officials that the then opposition Fianna Fail leader was responsible for “potentially dangerous” actions to undermine the Irish government’s policy on Northern Ireland.
Then Prime Minister John Major and the governing Fine Gael’s John Bruton had enjoyed a warm relationship, with officials at the time hoping “that in our interest he should remain in position”.
The 1997 Irish General Election saw Mr Ahern’s Fianna Fail gaining seats, before entering into coalition government with the Progressive Democrats.
Within the files released on Wednesday was a review penned in 1995 by the British ambassador to Ireland, Veronica Sutherland. In it she wrote that Mr Ahern’s leadership of Fianna Fail had been weak and added that in her view “there is little to fear from the Opposition”.
“Bertie’s Ahern’s leadership of Fianna Fail has been lacklustre, and his attempts to undermine the Irish government’s policy on Northern Ireland potentially dangerous,” she added.
Elsewhere the a memo from John Major’s private secretary Roderic Lyne, details a January 1996 meeting he had with senior military commander Roger Wheeler, in which the commander concluded that the IRA “were primed to return to full-scale violence” during the period.
He added: “In some ways, their military effectiveness had benefited from the ceasefire. They had improved their intelligence, targeting and recruiting.
“The drug murders had kept some of the units in practice and had shown that they were still very effective.”
Ambassador Sutherland’s notes also reveal there was recognition within the political sphere at the time about the declining influence of senior Sinn Fein figures over the IRA.
Following the London Docklands bombing in February 1996 the files revealed a discussion between Mr Ahern and the ambassador, in which the man advised he would be doing some “tough talking” to Gerry Adams.
Ms Sutherland added that Mr Ahern seemed “unsure whether this would have any effect” adding that “in his view, Adams no longer had any influence over the IRA”.
Despite the cooperation between the two governments leading to the 1997 Good Friday Agreement, the files reveal tensions that existed at the time under the surface between key officials.
“In general the Irish attitude to us remains ambivalent – and volatile. They are suspicious of our motives, and quick to blame us for set-backs,” wrote Ms Sutherland.