The son of nuclear physicist Yves Rocard, he entered politics as a student leader while he was studying at Sciences Po.

[2] Having left the SFIO because of Guy Mollet's position towards the Algerian War, Rocard led the dissident Unified Socialist Party (PSU) from 1967 to 1974.

Some months later, he was elected deputy for the Yvelines département, defeating the former Prime minister Maurice Couve de Murville.

As the Socialist Party's most popular politician at the time (including Mitterrand himself),[citation needed] he announced that he would run for president; but his "Call of Conflans" did not result in majority support within the PS, and he withdrew his candidacy.

From the 1970s to the 1990s, Rocard's group inside the Socialist Party, known as "les rocardiens", advocated a re-alignment of French socialism through a clearer acceptance of the market economy, more decentralisation and less state control.

It was largely influenced by Scandinavian social democracy, and stood in opposition to Mitterrand's initial agenda of nationalization, programmed in the 110 Propositions for France.

[citation needed] However, according to Mauroy, who led the party, Rocard stood as the "natural candidate" for the following presidential elections.

[citation needed] After the 1993 electoral disaster, he became leader of the PS by advocating a political "big-bang", that was to say a questioning of the left/right divide.

[citation needed] Rocard remained as leader of the Socialist Party for only one year, in part because of the PS's complete defeat during the 1994 European elections.

The defeat was in part due to the success of the list of the Left Radicals Movement, which was covertly supported by President Mitterrand.

Michel Rocard was known for his hostility for proposed directives to allow software patents in Europe, and has been an outspoken opponent of what he considers to be manoeuvres to force the decision on this issue.

Rocard also publicly admitted, after the election, having asked Ségolène Royal to step down in his favor in March 2007, one month before the first round of voting.

[6] He furthermore explained that he had accepted to speak before the Gracques' spring university (a group of senior left-wing civil servants who advocated a centrist strategy) because political parties were not suited any more to serious reflexion.

[6] He remained active in European Union politics as late as June 2014, when he delivered his thoughts on the British on the 70th anniversary of the D-Day landings in Normandy.

Rocard quoted Churchill's words about the "United States of Europe", issued a strong condemnation of the UK policy of the 40 years to that date, and begged for a European strongman, which he saw in Martin Schulz.

In June 2007, Rocard was admitted to the Calcutta Medical Research Institute, Kolkata, India where doctors found he had a blood clot in the brain and was operated upon.