Gerry Adams wrote to Tony Blair on the very day his New Labour government swept to power, assuring him Sinn Fein would be “totally committed” to bringing peace to Ireland, previously private correspondence between the two men shows.

Mr Adams and Mr Blair were among those noted for their roles in bringing about the Good Friday Agreement in 1998 after years of bitter conflict between republicans and loyalists in Northern Ireland known as The Troubles.

Documents on Anglo-Irish relations from Mr Blair’s first few days in office show Mr Adams was keen to signal his co-operation from the outset.

In a letter from the Sinn Fein president, on personalised paper to Number 10 and marked May 2 1997, Mr Adams wrote: “Be assured that this (peace in Ireland) is a priority for me also and that Sinn Fein is totally committed to democratic and peaceful methods of struggle and to a negotiated settlement to the conflict in our country.

“The rebuilding of a credible peace process must be tackled without further delay.

“While I am mindful of the difficulties for all concerned, I remain confident that the peace process can be established on a solid basis of equality and inclusive dialogue.

“That is certainly my commitment.”

Mr Blair’s response, again in a private letter released by the National Archives in Kew, appeared firm.

“You and those you represent should also be in no doubt as to the Government’s fundamental approach in seeking to promote reconciliation and overcoming the divisions which have contributed to conflict,” he wrote.

“It is fundamental that such negotiations can take place only among those committed to exclusively peaceful methods and who have shown that they abide by the democratic process.

“We shall not be diverted by violence or threats of violence. It is vital that there should be no misunderstanding about our approach and our commitment to follow it through consistently.”

Mr Blair called for the restoration of an IRA ceasefire, which duly came into force in July.

In October, Mr Blair and Mr Adams shook hands during a historic meeting in Belfast, while Mr Adams met the PM in Downing Street two months later.