The French government decided today to extend its ban on British beef, a surprise move that portends more fireworks in the Great Beef War of 1999 and more heated debate here about Britain's place in the European Union. After a meeting of Prime Minister Lionel Jospin's cabinet in Paris, government spokesman Daniel Vailland said, "For now, there cannot be a unilateral lifting of the embargo. The conditions set by France in the name of prevention and health are not being fulfilled."

The decision puts France, long one of the strongest proponents of a united Europe, in the uncomfortable position of flouting a clear mandate from the EU. Two weeks ago, an EU scientific panel ruled unanimously that British beef is safe to eat, meaning that no member state can legally block imports.

The announcement in Paris also puts a political squeeze on Prime Minister Tony Blair. For weeks, the London tabloids and anti-Europe politicians have been demanding an outright trade war over the ban. Blair has refused, arguing that his policy of "constructive engagement"--that is, quiet negotiation through EU channels--offered the best chance of opening the French market.

France's decision to ignore the EU mandate on beef made mincemeat of Blair's cautious position. And the announcement from Paris came just in time to be the prime topic today in the House of Commons.

William Hague, the leader of the opposition Conservative Party who is deeply skeptical of greater British engagement with the EU, roasted the Labor Party government on the beef issue. Would the prime minister agree, Hague asked in a voice laced with disdain, "that the French decision is a total humiliation for this spineless government?"

Blair did not agree, but instead restated his basic position: His government will continue to negotiate with the French. But if Paris does not give in, Britain will bring a case in the European Court of Justice, charging France with creating an unjustified unilateral trade barrier.

In the constant political infighting here over Britain's role in Europe, Blair's stance toward the EU is generally backed by the third-largest party, the pro-Europe Liberal Democrats. But today, not even the Liberals' leader, Charles Kennedy, was willing to defend Blair's decision to work within the European system.

British beef was banned around the world following the "mad cow" epidemic here in the mid-1990s. But British farmers culled their herds and made huge investments in new stock and equipment to produce healthy beef. On Aug. 1, the EU declared British beef safe to eat, and all member countries except France re-opened their markets to imports.

Britain then took the issue to the EU's scientific committee, and the scientists found no basis for the French position.