The secret plan, which was seen as a bid to protect France's Fifth Republic and to keep public order by the officials who drew it up, included delaying the handover of power from Hollande to Le Pen and keeping the outgoing president as head of state until after next month's parliamentary elections.
That way, Le Pen would not have been in a position to appoint her own prime minister. The officials were calculating her National Front party wouldn't secure a parliamentary majority, forcing Le Pen to accept a prime minister and Cabinet selected by opposition parties.
'It was like a multistage rocket,' a senior official told L'Obs, a weekly news magazine. 'The philosophy, and the absolute imperative, was to keep the peace, while also respecting our constitutional rules,' he added.
The plan, which at the very least would have skirted convention, did not have to be put into operation because centrist Emmanuel Macron pulled off a crushing victory, defeating Le Pen by a two-to-one margin.
FILE - New French President Emmanuel Macron, right, smiles as outgoing President Francois Hollande waves during Macron';s inauguration ceremony as French President, at the Elysee Palace in Paris, May 14, 2017.
The first goal in the mind of the plan's participants was freezing the political situation, according to officials who spoke with French newspapers, and preventing violent civil unrest. The second was to restrain Le Pen.
In the run-up to the elections, French media reported police and intelligence chiefs were alarmed at the prospect of the anti-immigrant and anti-EU Le Pen winning, and they worried France would be drawn into chaos with left-wing protesters refusing to accept the result. In April, Le Parisien, a daily newspaper, reported on a confidential memo drafted by intelligence chiefs saying every local public safety directorate was expressing concern about the consequences of Le Pen being elected.
Officials told L'Obs that under the overall plan to manage a Le Pen victory, parliament would have been recalled in emergency session. 'The country would have come to a halt and the government would have just one priority, assuring the security of the state,' an official told the weekly magazine.
Future for party, Le Pen
Meanwhile, Macron's decisive win over Le Pen has shattered National Front unity, with recriminations flying over the heavy defeat.
'Rarely in French political history had there been such a confluence of favorable conditions for the election of an extremist and populist candidate in a presidential race: a lingering EU migrant crisis, the soaring recurrence of actual and prevented terror attacks throughout the country, increasing segments of French society feeling disenfranchised, a growing voters' fatigue with worn-out manifestos by self-seeking traditional parties, and a stagnating national economy; all seemed essential ingredients for a majority vote in favor of Marine Le Pen,' notes analyst Solon Ardittis of the Germany-based Institute of Labor Economics, an independent research institute.
FILE - A person holds a mask of France';s National Front (FN) defeated presidential candidate, Marine Le Pen, as people gather with French and European flags near the Eiffel Tower and a banner with the message, 'France tells Hate: Never Again '
Party critics of Le Pen agree with that assessment - and it is driving rifts within the National Front. Le Pen, who will contest a seat in next month's parliamentary elections in a mining town in northern France, insists her party still has an essential role to play in French politics and that she will remain at the head of it.
'We are, in reality, the only opposition movement. We will have an essential role to play [and] a role in the recomposing of political life,' she told a French television channel on Thursday.
One of her nieces, 27-year-old Marion Marechal-Le Pen, a rising political star, and one of only two National Front lawmakers in the outgoing parliament, announced this week she's quitting politics. And Le Pen's deputy, Florian Philippot, is now forming his own 'patriotic' movement.
Opinion polls are now suggesting that the one-year-old party of France's newly elected Macron, the youngest leader of the country since Napoleon Bonaparte, is surging ahead of next month's parliamentary elections. A survey puts his La Republique en Marche party at 32 percent of the vote, 13 percent ahead of its nearest rival, Les Republicains.
Macron's choice of Cabinet members - some prominent figures, others unknown but all drawn equally from the right and left of French politics - has also gone down well with the public, with a 61 percent approval rating.
Le Pen's defeat has been greeted by many European liberals as a sign that the populist wave that's been washing across Europe has now run its course. Some analysts, however, say that the populists shouldn't be counted out yet. Macron's victory, argues Robert Skidelsky, a political economist at Britain's Warwick University, amounts to a win in one battle and not the end of the war. 'The idea that one in three French citizens would vote for the National Front's Le Pen was inconceivable only a few years ago,' he said.