The Democratic Unionist Party is to block any bid to have an Irish Language Act passed in the Northern Ireland Assembly, according to a letter signed by party leader the Rev Ian Paisley.
In the two-page letter, written to mark the first 100 days of the Stormont executive, the First Minister assures party members that the DUP will oppose any legislation that was would enshrine the rights of Irish language speakers.
DUP leader Ian Paisley
A language act is a key demand from Irish language advocates who say it deserves the protection granted to other minority languages across Europe.
"Under DUP stewardship, unionists are now confident that the Union is secure," the North Antrim MP said.
"We have transformed the political landscape despite many of our opponents saying it was impossible. Some even attempt to rubbish the significant gains we have made but we have defeated terrorist objectives and safeguarded unionist interests."
He added: "The DUP will not support the creation of any such legislation.
"This was a proposal made by the two Governments (British and Irish at the St Andrews talks) and was never agreed to or even discussed with us.
"As a result of the changes we secured on the decision-making process in the Assembly, the Irish language legislation would require unionist support in the Executive."
Earlier this year, the Council of Europe called on the British government to develop a comprehensive Irish language policy, including measures to meet the increasing demand for Irish-medium education "as a matter of priority".
The Strasbourg-based Committee of Ministers backed the findings of an 86-page report from a Council of Europe watchdog monitoring the European Charter for Regional or Minority Languages, which came into force in the UK in July 2001.
The Charter commits the British government to safeguard and promote Welsh, Scottish Gaelic, Irish, Scots, Ulster-Scots, Cornish and Manx Gaelic.
In the North, where demands for an Irish Language Act similar to the south's Official Languages Act, the Democratic Unionist Party has branded the proposal for an language act as divisive and discriminatory and "sponsored by Sinn Féin".