The decision of the European Commission to resign is a first in the history of the EU and propels its institutions into an unprecedented constitutional crisis.
For one thing, the timing is appalling. A summit next week is supposed to resolve fundamental differences over the budget for the next seven years. Like it or not, in Berlin the heads of government, to their intense surprise, may have to spend some of their time deciding how to fill one of the most important political jobs in the EU, that of President of the European Commission.
And they will have the help in the Agenda 2000 talks of a caretaker Commission whose authority in the negotiations will be severely diminished, a prospect that the smaller member-states will view with some apprehension. Indeed, the assertion of parliamentary authority is likely to be viewed in Dublin with less than enthusiasm at this crucial stage of the talks.
But the deal will be done on Agenda 2000, and probably in Berlin.
The clash between the EU's executive branch - the Commission - and the legislative - the Parliament - in which the latter has clearly comes out on top has marked, however, a significant change in that balance of institutional forces which Ireland has regarded as crucial to its interests. And there can be little doubt that once the genie is out of the bottle it will not be put back.
Parliament asserted itself last night in demonstrating to the other institutions that it can no longer be taken for granted as a passive partner in the management of the EU's affairs. By threatening the Commission with its power of censure it has forced its resignation; no future Commission will take MEPs for granted.
Yet that power to censure is part of Parliament's rights under the treaty - paradoxically, perhaps, their exercise of their theoretical rights last night may not in the long term be as significant as their attempt in January to assert their political, if not legal, right to sanction individual commissioners.
In effect, MEPs then made it politically impossible for prospective commissioners to face a future parliamentary hearing on their nomination without accepting the principle that they can be individually sanctioned by Parliament, despite the treaty reality that they can be only sacked as a group.
The significance of last night's enforced resignation lies in the gradual but qualitative transformation of the relationship of the Parliament to the Commission into one of a traditional parliament and a traditional government. The balance between the institutions is changed forever.
The report into alleged corruption and nepotism in the Commission which prompted the mass resignation also marks an important change in the culture of European public administration, as Irish MEP Mr Pat Cox pointed out last night.
The Commission has traditionally embodied not one culture of public service but the traditions of as many cultures as there are member-states. A new openness and transparency has been introduced in part by the accession of the "puritanical" Nordics and in part by the profound challenges to croneyism and political corruption that have swept all the "southern" member-states.
Patronage, favouritism and croneyism are no longer acceptable in the way they were a way of life in the commissions of the past. Now we have open competitions, tenders for contracts, codes of conduct for commissioners and declarations of interests.
But often the inertia of institutions takes time to catch up with the realities of the new world. Last night the Commission caught up with a vengeance.
Need the result have been as brutal? Perhaps not if the Commission and particularly its President had seen the signs coming and responded with a degree of determination to the problems.
The truth is that Mr Jacques Santer's handling of the gathering storm was at best hamfisted, at worst bizarre. At times the Commission's senior spokespersons have left hostile press briefings saying, "crisis, what crisis"? The tendency was to shoot the messenger rather than examine the message, to minimise the "administrative problem" rather than accept the need for wholesale reform.
In defying the Parliament over the discharge of the budget and making it an issue of confidence he effectively abandoned the treaty requirement for a two- thirds majority for sacking to a simple majority.
A congenial President appointed by the member-states as a safe pair of hands who would not rock the boat, or challenge the authority of the member-states, was not able to rock the boat when that is exactly what was needed.