Mr Chirac, Prime Minister under Mr Mitterrand during the 1986-88 cohabitation after the right won elections while the Socialist President still had two years to serve, said in a television interview that 'morals and dignity should lead the President of the Republic this time to draw the conclusions' and leave office if the right wins.
Mr Chirac, reconfirmed as president of the Gaullist RPR party this week, is currently best placed to win a presidential election, according to opinion polls.
There has been constant speculation that Mr Mitterrand, diagnosed to have cancer of the prostate, might soon choose to step down after gaining the victory he wanted for the 'yes' vote in last Sunday's referendum on the Maastricht treaty. Mr Chirac's words were an apparent attempt to put on the pressure for a complete change of political power. The ruling Socialist Party is at a very low ebb and its chances of recovery by March are slim.
Although Mr Chirac led the 'yes' faction in his party, his refusal to envisage a new cohabitation coincides with the view of the leaders of the majority Gaullist 'no' campaign, Philippe Seguin and Charles Pasqua, who were both ministers in Mr Chirac's 1986-88 cabinet.
It was hardly likely to please the patrician Edouard Balladur, who was Mr Chirac's finance minister and has been tipped as a likely choice for prime minister if Mr Mitterrand does stay on for a cohabitation bis. The Gaullist 'no' campaigners have singled out Mr Balladur as one of the leaders with whom they are most out of tune. So Mr Chirac's statement could be seen as an olive branch to the 'no' faction as well as an attempt to draw the battlelines in the fight against Mr Mitterrand.
The first experience of cohabitation was a bitter one for the Gaullists and their allies in the centre-right Union for French Democracy (UDF). The President kept the reins on foreign policy and defence and was wont to criticise the actions of what was theoretically his own government, becoming a sort of dissident-in-chief. In 1988, he easily won the presidential election against his own prime minister, threw new parliamentary elections and formed a Socialist government.
However, there was a fresh dissonance in Gaullist ranks yesterday as Jacques Chaban-Delmas, who was prime minister from 1969 to 1972 under Georges Pompidou, the last Gaullist president, said that it was constitutionally impossible to hold 'a government strike'. The new parliamentary majority formed after the next general elections would be simply obliged to govern, he said.