The Rev Ian Paisley's Democratic Unionist Party has now defined its terms for entering into direct dialogue and negotiation with Sinn Féin.
While admitting the DUP has "set the bar pretty high", the British government regards the development as a further signal that the majority unionist party is serious about the political process leading to the restoration of a fully inclusive devolved government at Stormont.
With the main focus of Tuesday's Hillsborough talks on Sinn Féin and the need for IRA "acts of completion", the British Prime Minister, Mr Blair, and the Taoiseach, Mr Ahern, asked the DUP in what circumstances they would deal directly with the republicans.
The Irish Times understands the DUP stipulated a complete commitment to paragraph 13 of last year's British Irish Joint Declaration, and a verifiable act of IRA weapons decommissioning to be accompanied by a timetable for the completion of the decommissioning process.
Ministers and officials are hoping this proves to be an opening negotiating position. However, taken alongside Dr Paisley's assertion that "the door is open" to Sinn Féin to enter government on the same basis as other parties, it does appear to have further strengthened the determination of Mr Blair and Mr Ahern to try to secure a political breakthrough ahead of the European elections in June.
Talks "insiders" remain sceptical about the prospect of completing a negotiation permitting the restoration of a power sharing executive before September at the earliest.
However, London and Dublin have been encouraged by signals from the DUP suggesting that the right conditions could be set in place relatively quickly, even as they harbour doubts about the DUP's likely response should Sinn Féin in turn seek to engage the governments and parties on the range of issues left unresolved by last October's failed UUP/Sinn Féin negotiation.
Unionists and republicans are expected to feel "pain" in equal measure over the coming fortnight, with next Thursday's publication of the Cory report to be followed by the report of the Independent Monitoring Commission (IMC) on the Bobby Tohill affair.
But while London will await the precise terms of that report and take the chief constable's advice, the indications are that the British government will reject the Conservative proposal - backed this week by Ulster Unionist leader Mr David Trimble - that it withdraw official recognition of the IRA's ceasefire.
With the summer months approaching ministers are hoping that the prospect of further IMC reports will be factored-in by Sinn Féin in particular, and help prevent any large scale disturbances on Northern streets.
That in turn, however, reinforces the suspicion that, for all the insistence of the Taoiseach and prime minister to the contrary, major political decisions may not be taken before the autumn.