Charlie Haughey was warned about potential embarrassment from sponsoring a trust set up in memory of a British ambassador blown up the IRA.
The widower of Christopher Ewart-Biggs wanted the Taoiseach to take up where Jack Lynch had left off and put his name to a memorial fund in his name.
But some of Mr Haughey advisers cautioned that he could end up sponsoring a lecture given by the likes of pro-unionist politician Conor Cruise O'Brien, papers from 1983 released by the National Archives reveal.
Mr Ewart-Biggs was killed on July 21 1976 when a landmine blew up under his car outside his home in Sandyford just 12 days after he took up the post.
In a hand-written note for Mr Haughey nine days after he took office in December 1979, an advisor warns that rejecting the invite from widower Jane would be widely misinterpreted in Britain but that he should take care not to get too heavily involved.
He was also warned Mr Haughey not to write directly to Mrs Ewart-Biggs for fear of starting correspondence with her.
"Mrs Ewart-Biggs is one of those well-intentioned but pushy individuals whose attention can be bothersome at times," an adviser wrote to the Taoiseach.
"While the trust's aim are unexceptionable you might have preferred to remain uninvolved in the absence of her invitation.
"However since she has issued it, I recommend that you accept since we can ensure in practice that your sponsorship does not involve you in any burdensome activity and since a refusal could be misinterpreted.
"I should however point out that in the past the trust has promoted lectures by Conor Cruise O'Brien which were along lines, divergent from government policy."