Redrawing Northern Ireland’s border would be a “fatal mistake”, ex-Irish premier Garret FitzGerald privately warned Margaret Thatcher, secret files have revealed.
During robust, rapid-fire exchanges at a critical summit in the run up to the Anglo Irish Agreement, Mrs Thatcher argued that giving Dublin an official role in the running of the region would plunge it into civil war.
Venting her fears that the North of Ireland was heading towards a Marxist state, the Conservative Party leader told her Irish counterpart in the November 1984 talks that resolving the crisis could mean “simply” moving the border.
“She wondered if a possible answer to the problem might not simply be a redrawing of boundaries,” records an official note of the top-level meeting, which has only just been declassified under the 30-year-rule.
But Taoiseach Mr FitzGerald immediately rejected the apparent offer, warning it would be a “fatal mistake”.
“What we have achieved at present is a lowering of expectations,” he said.
The pair later discussed a federal Belgium-style model.
Mr FitzGerald said the Irish government had worked on dampening down hopes among some for an end to Northern Ireland, as it was constituted.
Most people had accepted “unity was not on” in the short run.
The Taoiseach, and then Fine Gael leader, pressed Mrs Thatcher for a new “system” of governing Northern Ireland, based on agreed policies between Britain’s secretary of state and an Irish government minister.
Where they could not agree, decisions would be appealed to the Prime Minister and the Taoiseach, he said.
But Mrs Thatcher “reacted strongly” to the plan, according to the Dublin government files.
“No, no - that is joint authority,” she said.
“You are giving them 40% of our country.”
The British Prime Minister said Catholics in Northern Ireland, who made up 40% of the population, argued that they owed no allegiance to London “but they took the Government’s money”.
They thought they were different to any other minority and were “drawing on resources which the Republic did not provide,” she told Mr FitzGerald.
“The nationalists feel that all they have to do is to wait.”
She accepted there were problems with Catholics getting jobs and admitted some areas - pointing to Lisburn as an example - “would not accept Catholics”.
Mr FitzGerald said there had been agreement on an Irish government role in running the region, adding that he could not ask the nation to give up its territorial claim over Northern Ireland without such a deal.
But Mrs Thatcher insisted: “It smacks too much of joint authority. That was definitely out.”
She added: “The unionists would say you are giving up your Constitutional claims but you are coming across the border and don’t really need the claim. That would put us well on the way to civil war.”
Her then Northern Ireland Secretary Douglas Hurd could “no longer manage” and she would not “fetter his judgment in that way”, she said, urging the Taoiseach to “please understand that”.
During one sharp exchange, as she argued that Westminster was answerable for Northern Ireland, Mr FitzGerald retorted that “for 50 years they had not regarded themselves as being answerable”.
“They had never permitted a question on Northern Ireland to be discussed in the house,” he said.
“That was partly the reason for the present trouble.”
On a suggestion from the Taoiseach of a Belgium-style solution - a federal arrangement under a monarchy- Mrs Thatcher said she “had not ruled it out, even though it would be attacked by unionists as an effective repartition.”
She added: “History shows that the Irish, whether the Scottish-Irish or the Irish-Irish, don’t like to move. However, they all seem to be terribly happy to move to Britain.”
Mrs Thatcher complained there was too much public sector employment in the Northern Ireland, there was no wealth creation and that it was costing London £2 billion a year in subventions at the time.
During the two-hour meeting at her country house retreat Chequers, the Prime Minister said there was worries about a threat of more violence as a result of the Anglo-Irish talks.
“There was a real danger that a Marxist society could develop,” she added.
Mrs Thatcher questioned if there could be no devolution would it be best to have proper local government or to “treat Northern Ireland as simply another part of the United Kingdom”.
Later that day, in a press conference, Mrs Thatcher gave her infamous “out, out, out” declaration, when she rejected three options put forward from the Irish for a solution to Northern Ireland - Irish unity; a two-state federation; or joint authority.
It was later reported that Mr FitzGerald thought her behaviour was “gratuitously offensive”.