In a pamphlet published today by the Fabian Society, a left-wing British think-tank, Mr Jospin seeks to play down his differences with Mr Blair over the future direction of centre-left parties.
But unmistakable differences of emphasis between the two leaders emerge in the Jospin statement, which will be discussed at a high-level summit in Florence this weekend on "progressive governance for the 21st century". It will be attended by Mr Jospin, Mr Blair, President Bill Clinton, Germany's Chancellor Gerhard Schroder and the Italian Prime Minister Massimo D'Alema.
After an initial spell of cool relations, during which Mr Blair's aides branded Mr Jospin as "Old Labour", the two men moved closer together. But in recent weeks Downing Street has become increasingly exasperated with the French government's refusal to lift the ban on British beef.
Outlining his version of "modern socialism", Mr Jospin defended the French "social model" and his government's introduction of a 35-hour week, saying it has created or saved 120,000 jobs.
He took a markedly different view to Mr Blair over the global economy, on which the Blair Government is much closer to the Clinton administration.
While admitting countries must "adapt to reality", he insisted that capitalism must be regulated, and said: "We can shape the world according to our values."
Mr Jospin called for European social democrats to work together, but warned that national differences over "historical roots, ideological ref- erences and political landscapes" must be recognised.
Comparing the French and British governments, Mr Jospin pointed out that Mr Blair enjoys a big overall majority while his own administration in Paris is a coalition of five parties.
"So in my opinion there is little point in choosing between `the Blair way' or `the Jospin way'," he wrote.
"If the Third Way lies between communism and capitalism, it is merely a new name for democratic socialism peculiar to the British. But this does not mean that we have the same approach in France.
"If, on the other hand, the Third Way involves finding a middle way between social democracy and neo-liberalism, then this approach is not mine."
Mr Blair has denied that this is the aim of his "Third Way", although his critics inside the Labour Party have attacked it as a return to the free-market policies of Margaret Thatcher.
But Mr Jospin insisted the "same project" of reshaping theory and practice had been embarked upon by all Europe's social-democratic parties.
He also offered a concession to Mr Blair, saying that socialists should aim to end the class divide and to "reconcile the middle and working classes".