The British Prime Minister, Mr Tony Blair, has defended the British decision to proceed with the Mox plant at Sellafield despite strong objections yesterday from the Taoiseach Mr Ahern.
The two leaders discussed the issue yesterday in Dublin Castle at the first meeting of the British-Irish Council for two years.
The council, one of the institutions established by the Belfast Agreement, has not met since December 1999 due to the crises in the peace process.
Mr Blair told a joint press conference yesterday that he believed the British government was adhering to rigorous safety standards. He said that if there was any risk associated with Sellafield it would affect British as well as Irish people. He said the Taoiseach had made the Irish case "very forcefully and I entirely understand the concern that people have here in the Republic of Ireland".
However if workers at Sellafield lost their jobs for reasons that did "not appear to be based on evidence or in accordance with the standards that have been laid down" that would be a serious problem for him.
Mr Ahern also pressed for a date to be set for a meeting between the Northern Secretary, Dr John Reid, and Mr Justice Baron, who is inquiring into the 1974 Dublin and Monaghan bombings.
The Government has said in the past that the British have been slow to hand over documents relating to the attacks, and had failed so far to agree a date for a meeting with Mr Justice Barron.
Mr Blair said: "The Secretary of State for Northern Ireland will meet Mr Justice Barron and the sooner that meeting can take place the better.
"We want to co-operate in any way we can. I totally understand the concern of the relatives of those people who died in those terrible attacks of terrorism."
The Taoiseach said he welcomed the statement that Dr Reid would meet Mr Justice Barron.
On the eve of today's crucial Ulster Unionist Council meeting in Belfast, both leaders said they would not tell unionists how they thought they should vote.
However both pointed to what they said were major advances for the unionist community through the he working of the agreement.
Mr Blair said the unionist community should see that it has made a major gain in securing the principle of consent - that everyone recognizes that the consent of a majority in the North is required for a change in the constitutional position.
Both leaders highlighted the role played by the Executive in the solution of the confrontation at Holy Cross national school.
"Holy Cross was an example of something that couldn't be solved except by people on the ground and the Northern Ireland Executive managed to solve it", said Mr Blair.
Mr Ahern said it was hard to see "how anyone who believes in progress of any kind would not be very supportive" of Mr Trimble.
The successes of Mr Trimble's policies included the progress of the Northern Ireland economy and "issues of tourism and trade for the benefit of the entire population of Northern Ireland".