After four hours of discussion in Luxembourg, the French Foreign Minister, Philippe Douste-Blazy, failed in his bid to win unprecedented controls over Mr Mandelson's conduct of World Trade Organisation (WTO) talks.
But the row, centred on efforts to cut agricultural support, underlined the internal opposition within the 25-nation bloc to the liberalising agenda pioneered by Mr Mandelson.
Yesterday's meeting of European Union foreign ministers was convened at the request of France, which is the main beneficiary of EU farm subsidies.
Last week in Zurich and Geneva the United States offered to make cuts in its agricultural payments, and within hours Mr Mandelson responded with a counter-bid.
In world trade talks, the EU's position is negotiated by the commission from a mandate set by the 25 member states. However at least six countries were angered by a lack of prior consultation.
In a full-frontal assault on the commission, M. Douste-Blazy demanded the creation of a new committee to assess the social and economic impact of any new negotiating position adopted by the European side in the talks.
The French Foreign Minister described Mr Mandelson's approach as "unacceptable", arguing that member states took "political responsibility" for decisions made by the EU.
As the scale of the attack became clear, Mr Mandelson reacted angrily, telling journalists: "If taken literally, that procedure would stop the Doha [world trade] talks in their tracks."
The trade commissioner won backing from the UK, which holds the presidency of the EU, including the Foreign Secretary, Jack Straw, who was once seen as a domestic political enemy of Mr Mandelson when he was a cabinet minister.
Mr Straw argued: "No negotiation is ever possible if you have to negotiate not only with the people in the room but also with some other committee in permanent session. It frankly makes negotiations impossible and it renders your negotiators powerless."
In the event EU member states rejected the French plan, though experts will meet today in Geneva to discuss the commission's latest position.
Mr Mandelson said the commission had agreed to use a scheduled meeting today to brief other member states on the impact of last week's EU negotiating offer, adding that there had been "no change of any sort" in the procedures.
The trade commissioner said today's meeting "will look backwards at the proposals made by the commission last week," arguing that consultation "is not the same as a new procedure or mechanism to monitor" the commission.
Despite Mr Mandelson's victory, the fact that such a public battle had to be fought underlines the problems he faces in the run-up to crucial world trade talks in Hong Kong in December.
The commission accepts that it has a huge problem in keeping Paris on board, particularly in the changed political climate following the rejection of the European constitution in a French referendum. Privately, EU officials question whether France is committed to getting a deal in the world trade talks at all.
Thirteen of the 25 EU countries have signed a letter to the EU agriculture commissioner, Mariann Fischer Boel, insisting that the commission does not exceed its mandate on farm subsidies in the WTO.
In the talks yesterday Ireland, Spain, Portugal, Cyprus and Hungary all offered some support to France, without pressing hard for the establishment of a new committee.
Spain's Foreign Minister, Miguel Angel Moratinos, said: "The art of negotiation is to have sufficient flexibility inside the negotiating parameters, but what I do not want is to have surprises at the end."Reuse content