By Kevin Connolly BBC Ireland correspondent

Northern Ireland's peace process has undergone a remarkable transition in the last six months.

The substance of the problem - the creation of political institutions in which Catholics and Protestants can comfortably share power - was intractable then, and remains intractable now.

Relative peace has fallen across republican areas of Belfast

But the change has been in the atmosphere and the language surrounding the search for a deal to revive the province's devolved institutions in time to allow elections to take place on 29 May.

Suddenly, the to-ing and fro-ing between the republican leadership and the governments of Britain and Ireland, which is the basis of the whole process, is being conducted in the open and in plain language after years of secretive negotiations conducted in heavily-coded waffle.

They are searching, remember, for a statement from the IRA strong enough to tempt Ulster Unionists back into sharing power with republicanism's political wing Sinn Fein.

The IRA's first offer was a statement which included words to the effect that their "strategies and disciplines would not be inconsistent with the Good Friday Agreement".

In the past, such wordy declarations have often done the trick in restoring momentum to the peace process precisely because they have a certain vagueness about them which would allow republican leaders to present them to unionists as a compromise, and then to argue to their own base that they had not actually shown any weakness.

Blair's tough new mood

This time though, they found Tony Blair in a new and very different mood.

He came to Belfast in October last year and delivered a powerful speech calling for acts of completion and arguing that a transitional phase in which the republican movement could have both a paramilitary and a political wing had come to an end.

In the new jargon it was time for "acts of completion".

Tony Blair has decided to get tough with Sinn Fein

In the last few weeks he has proved he meant every word of it, allaying unionist fears the British Government is so desperate to do a deal to end political violence in Northern Ireland it would accept almost any amount of prevarication from Sinn Fein.

In an extraordinary move, he went public, with three direct questions for republican leaders about whether or not the IRA was saying it had done definitively with violence.

'IRA committed to peace'

Gerry Adams answered with a public declaration that the IRA was wholly committed to peace.

It was another part of his dialogue with the British establishment which would once have been conducted secretly.

Mr Blair's response set a new benchmark for bluntness in a process hardly famous for clear unambiguous public declarations.

He said the IRA had to declare it would no longer be involved in rioting, procuring weapons, putting people into exile and administering punishment beatings - all things that republicans tend to deny anyway but people who live in Northern Ireland know or suspect go on.

Angry Adams

Mr Adams angrily declined to be so specific.

He would say it is because republicans will not dance to a British or unionist tune.

His critics would say it was because republicans want privately to reserve the right to continue with some or all of those activities.

Gerry Adams is being urged to say the war is over

Any hope of doing a deal to get David Trimble back into power-sharing, and thus into elections was gone, not least because Mr Trimble would have to sell any deal to the Protestant electorate in the face of a challenge from Ian Paisley's anti-agreement Democratic Unionists.

Nationalist Ireland - including the Irish Government - is outraged.

In its analysis, Irish political rights are being shown to be at the mercy of a stroke of a British pen.

In Sinn Fein's view the British Government which suspended democracy is the same as the British Government which once presided over security forces who colluded with loyalist killers.

They believe London does not have the moral high ground.

For Mr Blair, this is all about practical politics.

Reluctant to postpone polls

As a democrat, he recoils from postponing elections and has done so only because he feels a vote in Northern Ireland on 29 May just would not produce workable political institutions.

The search for a settlement will resume, and will intensify in the autumn, and as always will be fraught and difficult. All sides like to ask other parties to the peace process for clarity and certainty.

When the debate resumes, it will be much more open than in the past, it will be conducted in much direct language, and it will deal with concrete issues in a concrete way.

The business of following the debate may become a little easier - but the search for a solution certainly will not.