In theory, he has it in his power to do so. The election is balanced so finely that the Front's first-round voters hold the destiny of France, conceivably of Europe, in their hands.
Jean-Marie Le Pen could advise NF voters at a giant rally in the Paris suburbs tomorrow night to swing left where their own candidates have been eliminated. However, to do so would jeopardise the chances of a handful of NF candidates, including his own daughter, Marie-Caroline.
The Front scored its highest ever total - 15 per cent of the vote - last Sunday in the first round of a French parliamentary election. A record number of NF candidates, 133, including Marie-Caroline Le Pen, west of Paris, survived into the second round this weekend.
Mr Le Pen's instinct is to urge FN voters to vote for the left in the more than 400 constituencies in which their candidates have been eliminated. The normal pattern would be for 40 per cent of FN voters to switch to the centre-right, 20 per cent to the left and 40 per cent not to vote at all.
If Mr Le Pen could disturb this pattern, he might tip the election towards Lionel Jospin, the Socialist leader, consigning President Chirac to five years of co-habitation with the left, humiliating the centre-right and creating more growing-room for the NF. A left victory would also throw into doubt the timetable for Economic and Monetary Union (EMU), which Mr Le Pen opposes.
But the left is the main threat to the FN in the half-dozen or so constituencies where it has a chance of winning seats in the National Assembly. If Mr Le Pen is saying "Vote left", it becomes awkward for FN candidates in these seats to urge centre-right voters to vote for the Front to "Keep out the left".
The seats in question include Vitrolles-Marignane, near Marseilles, where Bruno Megret, the de facto number two of the FN, and Mr Le Pen's insubordinate rival, is in a neck-and-neck, second round run-off against the outgoing Socialist MP. To lose this race would cause little grief to Mr Le Pen.
However, the FN also has hopes of winning two seats in Toulon in straight run-offs with left-wing candidates. And then there is Marie-Caroline Le Pen. She topped the first round poll in Mantes-la-Jolie, in the suburban departement of Yvelines, but the Socialist candidate, who came third, could win on Sunday if she inherits all the first-round Communist voters.
The FN leader made several speeches during the first-round campaign in which he said he would prefer the left to win the election. But he was disowned in an unprecedented public display of dissension, not only by Mr Megret but by other, more loyal, FN leaders.
At a moment of triumph for the FN, Mr Le Pen's position within the party has been weakened by the rise of Mr Megret and by his own decision not to run in any constituency (for fear of losing while Mr Megret won).
Tomorrow night he will probably back his instinct and say "Vote tactically left", while trying to make exceptions of the seats the NF could win.
Conversations in the Le Pen household after Sunday will be interesting if the formidable Marie-Caroline loses to her Socialist rival by a couple of hundred votes.