Fillon had consistently been polling third in surveys leading up to the election. French senator and key Fillon supporter Roger Karoutchi told reporters: "The first indications are not good."
The result, if confirmed, will mean a face-off between politicians with radically contrasting economic visions for a country whose economy lags that of its neighbours and where a quarter of young people are unemployed.
Though Macron, 39, is a comparative political novice who has never held elected office, opinion polls in the run-up to the ballot have consistently seen him winning the final clash against the 48-year-old Le Pen easily.
That in turn reduces the prospect of an anti-establishment shock on the scale of Britain's vote last June to quit the EU and the election of Donald Trump as US president.
Macron favours gradual deregulation measures that will be welcomed by global financial markets, while Le Pen wants to ditch the euro currency and possibly pull out of the EU. Whatever the outcome on May 7, it will mean a redrawing of France's political landscape, which has been dominated for 60 years by mainstream groupings from the centre-left and centre-right, both of whose candidates faded.
- AAP