The plans to attack Paris tourist sites and target “thousands of Christians” attending public events were uncovered after officers arrested an Algerian national based in southern France in June last year.
Police swooped on the 32-year-old butcher, named only as Ali M, as he tried to board a flight from Paris to Tunisia to meet a top figure in the terrorist group al-Qaeda in the Islamic Mahgreb (Aqim).
Officials have now revealed details of chilling e-mail messages sent to the al-Qaeda chief containing a list of potential targets in France.
On his hit-list were “the Eiffel Tower and the Louvre museum” as well as the Avignon Theatre Festival and a nuclear power station.
Ali M noted that “cultural events in the southern cities draw thousands of Christians over the course of a month”, according to Le Parisien newspaper.
He wrote: “The streets are filled with people and a simple grenade could wound dozens. I’ll leave it to your imagination the results of a car bomb.”
The married father of two also suggested attacking aeroplanes as they were taking off, as well as markets, nightclubs and bars.
But out of fear of accidentally killing Muslims during an attack, he said shopping centres should be avoided.
French officials said the man, who had been living in France for five years, was a “true zealot” determined to kill.
His lawyer, Daphne Pugliesi, told Le Parisien her client had been “brainwashed and tangled up with people much more dangerous than he was”.
She said: “The arrest was a relief for him.”
The foiled plot has emerged after figures revealed France has become the European centre for extremist activity.
Last year alone there were 225 arrests for terrorism offences, almost half of the total arrests across Europe in 2013. This puts France far ahead of Spain, on 99, and the UK, on 77.
There were also 63 attacks, including one that killed three Kurdish women in Paris.
In one series of arrests in March 2013, police found weapons and explosive material at the homes of three suspects arrested in Marignane in southern France. They reportedly sought to emulate the Jewish school gunman Mohamed Merah, 23, who killed seven people and injured five in three attacks which ended in his death in a police siege in Toulouse in March 2012.
Concerns are also mounting in France over the hundreds of residents who have joined the Syrian civil war to fight alongside jihadist militants.
Interior minister Bernard Cazeneuve is set to unveil legislation that bans foreign travel by individuals suspected of being radicalised, for up to six months. Under the proposal, their passports would be temporarily confiscated.
The legislation provides for harder measures against online recruitment, by, for instance, asking internet service providers to block access to sites “that provoke acts of terrorism or praise them”.
It will also allow investigators to use pseudonyms to go undercover on pro-jihadist sites.
France is also concerned by “lone wolf” terrorists who are homegrown and unaffiliated with larger radical networks.
This breed of attacker is harder to discover, having no accomplices, and may strike without much warning.
Last month, a Frenchman who had fought alongside jihadists in Syria, and who authorities called a “battle-hardened lone wolf”, was arrested in connection with a shooting at a Jewish museum in Brussels that killed four people.
Terror network with a grudge against west
THE terrorist group, al-Qaeda in the Islamic Maghreb (Aqim), operates in the west of North Africa, which includes Mauritania, Western Sahara, Morocco, Algeria, Tunisia and Libya. In the past two years it has also been active in Mali, but was driven out by a French military intervention in 2013. It was previously called the Salafist Group for Call and Combat, and was formed in 1998 as an offshoot of the Groupe Islamique Armee (GIA) active in Algeria, which lost popular support due to its involvement in massacres of civilians in a campaign against a military coup which sparked a civil war in 1992.
It joined up with al-Qaeda, now led by Ayman al-Zawahiri, in September 2006, declaring it would fight French and US interests in the Maghreb and is also said to have sent fighters to Iraq and more recently Syria.