BRUSSELS, NOV. 2 -- The new willingness of France and Germany to surrender key aspects of national sovereignty is widening the gulf between Britain and its continental partners over how fast and how far to push the process of political and economic union in Europe.

Prime Minister Margaret Thatcher's fierce defense of the British pound and the national parliament this week deepened her discord with other European leaders, whose readiness to move ahead with the next stage of European unity despite her opposition has become a source of embarrassment to British representatives abroad.

The resignation of deputy prime minister Geoffrey Howe over Thatcher's approach to Europe was viewed with dismay in this and other European capitals, where officials said the loss of a European advocate among senior cabinet members could make Thatcher even more adamant in her defense of national prerogatives.

On the other hand, the officials said, Howe's departure could prove useful if it shocks Britain into seeing that its suspicion toward Europe has become so self-defeating that it requires a radical change in policy, if not in leadership.

Britain's isolation has been magnified by the decision of France and Germany, the axis of European Community power, to cede important areas of national control to European institutions just when it appeared that their leaders might succumb to domestic political pressures and retreat from the grander ambitions of a more united Europe.

The endorsement by German Chancellor Helmut Kohl and French President Francois Mitterrand of new steps toward monetary union, greater legislative clout for the European parliament and an enhanced security role for the community at the recent Rome summit of EC leaders came as a pleasant surprise to officials and diplomats who conduct the daily business here of building a United States of Europe.

A month after Germany's unification, many European officials anticipated a burst of chauvinism in Bonn and Berlin that would be reflected in a more nationalist tilt by Kohl's government. Instead, Kohl agreed with other European leaders to set up a European Central Bank by 1994 that will eventually govern a single currency to supersede all others, including the strong German mark.

Even in agriculture, where Kohl and Mitterrand were accused by Thatcher of selfishly protecting their national farmers at the expense of reaching a community position on cuts in farm subsidies, there are signs that a compromise may be hatched so that the Uruguay Round of global trade talks can end on schedule in December.

Despite his anxiety about securing the German farm vote in national elections Dec. 2, Kohl kicked off his campaign in Dortmund this week with a strong reminder that as the world's largest exporter, Germany depends on an open world trade system for its prosperity and must make sacrifices to defend it. German political analysts said the speech, delivered only hours after he left the Rome summit, was a clear signal that Kohl is preparing to bend after creating the impression of having done all he could to help German farmers.

France, too, possesses a powerful domestic farm lobby that is seeking special protection from cheap imports to stay in business. While acutely aware of the political need to win compensation for the farmers, Mitterrand has told aides that he does not want their needs to thwart French support for a quantum leap toward European unity.

The French president, with four years to go before his second and last term in office expires, is eager to make his mark in history as the man who eroded the Gaullist foundations of French nationalism and established a new identity for his country in the vanguard of a European confederation. That goal was enshrined this week in a treaty of understanding and cooperation with the Soviet Union signed by Mitterrand and Soviet President Mikhail Gorbachev.

During Charles de Gaulle's final years in power, France became synonymous with the determined guardianship of national interests that is now closely identified with Thatcher's personality. But in the last decade, France has become an ardent supporter of European initiatives.

The decisive French turn toward Europe was reinforced by last year's democratic revolution in Eastern Europe, which spawned a bigger, united Germany in the center of the continent, nullifying any lingering French pretensions of dominating Western Europe.

The transformation of French attitudes toward the outside world has been a goal of Mitterrand since he was elected president in 1981 after being consigned to the opposition for most of his political life by de Gaulle's enormous stature. Indeed, the hope of displacing the legacy of de Gaulle has always been a central political motivation for Mitterrand, according to longtime associates.

That vision has gained greater credibility in an era when so much more became possible because of "the acceleration of history," as described by Jacques Delors, president of the EC's executive commission.