Winning only 14.5 per cent of the vote, the party's worst electoral result since being formed in 1971, there was only one option open to the party and that was to ditch its leader and look for new blood.
Mr Rocard finally got the message that it was time to call a vote of confidence from the 300-member party executive, but he was still so apparently out of touch with the strength of feeling against him that up until the last moment he was outlining his plans to revamp the party before the autumn.
Now after three decades trying to get to the top of French politics he finds himself on the scrap heap, while the Socialists try desperately to make themselves a credible political force once again.
Riven by personal rivalries and clan disputes, the Socialist Party must now find a new party leader and, more importantly, choose a candidate capable of filling the shoes of President Francois Mitterrand for next year's crucial presidential election.
After the Socialists' defeat in last year's general elections, Mr Rocard ousted another former prime minister, Laurent Fabius, to take over the leadership of the party. It was Mr Fabius who said at the weekend that the European Commission President, Jacques Delors, should become the Socialists' candidate for the April 1995 presidential poll. Mr Mitterrand has also made it known that he thinks that only Mr Delors is capable of keeping the centre-right's hands off the presidency.
First, however, the party will have to choose a new leader and among the names already being discussed are the flamboyant ex-culture minister Jack Lang and the former parliamentary whip Henri Emmanuelli. The 49-year-old Mr Emmanuelli will head the party until a scheduled congress this autumn or a special convention is called.
The Socialist Party has been in free-fall since it was ousted from power by the RPR-UDF centre-right coalition led by Edouard Balladur last year. Stained by multiple accusations of corruption while it was in power, some of the scandals reaching all the way to the Elysee Palace, the Socialists were a discredited force when the voters called for a change last year. Since then, the party has been in internecine warfare, allowing the Balladur administration to lead a charmed life despite an economic recession and unemployment now topping the 3-million mark.
Another problem for Mr Rocard was that he was on bad terms with Mr Mitterrand. Nevertheless, he managed to serve as his prime minister for three years, helping to change the Socialists' tax-spend-and-nationalise policies into a free-market austerity programme.Reuse content