THE resignation of Ian Paisley Junior from the Northern Ireland power-sharing Executive spells trouble in the weeks and months ahead for his father, Ian Paisley Senior, who is Northern Ireland's first minister.

Paisley Junior's resignation became inevitable because of the firestorm of criticism over his lobbying activities while serving as a minister in his father's office.

He was linked with a major developer and several multi-million pound schemes in his constituency. It seemed there were still more revelations to come, so he took the prudent course.

It is a huge blow for his 83-year-old father, who had wanted his son to succeed him some day as head of the Democratic Unionist Party (DUP). That was beginning to look unlikely in any event, but it will certainly not happen now.

His resignation will embolden the many Paisley critics within his own party who are uneasy over the alliance with Sinn Fein that Paisley has put together. Some of the traditional supporters of the DUP may also be having second thoughts.

The resignation comes at a time when Nationalists are calling for a date certain for policing powers to be devolved to the Northern Executive.

It is a vital step in ensuring that policing in all its parts comes under the remit of the elected Executive and does not continue to be overseen by Westminster civil servants.

There is strong resistance to this effort, and Paisley's party certainly is trying to delay the transfer. Despite that, hardliners in that party are still not satisfied with any arrangement with Sinn Fein on any level.

There was a straw in the wind on this issue in a local council by-election last week when an anti-Paisley candidate split the party vote, allowing a more moderate Unionist candidate to win.

Now the resignation of Paisley Junior will further hearten his father's critics to try and reverse the current gains in the peace process.

Given his advanced age and continued hands-off approach to policy matters, Paisley certainly seems vulnerable to a challenge from the right wing of his party.

The race to succeed him currently comes down to Peter Robinson, his finance minister who is considered a moderate, and Nigel Dodds, the economic development minister who is more hardline.

It seems hard to believe that even the hardest of the hardliners do not accept that power-sharing is here to stay, and the path set by the Good Friday Agreement cannot be obviated.

The success of the power-sharing government has meant that for the first time in decades Northern Ireland is undergoing a period of peace and prosperity unseen in its existence.

Yet there are forces on both sides that would willingly upset the careful equilibrium and bring chaos crashing all around.

Dissident IRA groups, no more than armed thugs, are threatening to restart a military campaign despite overwhelming evidence that Nationalists are widely in favor of power sharing.

Recalcitrant Unionists still cannot accept that the golden days of one party rule and no Catholics about the place in Stormont are gone forever.

It is still a fraught time, and much could still go wrong. The resignation of Paisley Junior is a clear sign that his father does not have the overwhelming power base he once had.

It is a time for caution and working hard to deliver the promises of the Good Friday Agreement, now reaching its 10th year anniversary.