Unionists were today asked to end their 23-year boycott of a body set up under the Anglo-Irish Agreement to foster good relations between Ireland and Britain.
Fianna Fáil TD and chair of the body, Niall Blaney said he has asked DUP leader Peter Robinson and Ulster Unionist leader Sir Reg Empey to take their seats on the the British Irish Inter-Parliamentary body.
The DUP and the Ulster Unionists have also been asked to submit proposals to rebrand the body.
Urging both parties to submit proposals for a change of name and direction of the inter-parliamentary group, established in 1985, Mr Blaney said the body was "not complete" without their participation.
"If the British Irish Inter-Parliamentary body is to have any effective purpose into the future, it must be with the unionists on board," he said.
Mr Blaney said the "relative peace" on the island of Ireland now called for the inclusion of unionists and a new focus on issues of mutual interest to all member parliaments, including tourism, health, the environment and drugs issues.
Originally established in an effort to improve good relations between Ireland and Britain, with members regularly updated on the peace process, Unionists have consistently refused to take up their five-seat allocation.
The Inter-Parliamentary body consists of 25 Dáil TDs 25 Westminster MPs and 18 members from each of the Scottish, Welsh, Northern Irish, Isle of Man, Guernsey and Jersey parliaments and assemblies.
However, it is unclear how unionists will respond to the Donegal North-East TD's request, as his roots are strongly linked to Irish republicanism.
Mr Blaney's father, Neil Blaney, and former Taoiseach Charles Haughey were both fired from their cabinet positions for their involvement in gun-running for the IRA during the 1970 Arms Crisis. His grandfather, Neal Blaney was an Old IRA member and TD in the Irish Government from 1927 to 1948.