France is to open de-radicalisation centres in every region to identify would-be Islamist extremists before they join jihadi groups, tackling what it called the most serious threat to the country since the Second World War.

The Socialist government announced the creation of a dozen “reinsertion and citizenship centres” across France as part of an 80-point plan to fight home-grown terrorism, which it unveiled on Monday.

The two-year plan includes a string of anti-terror measures aimed at combatting the growing number of young people in France drawn to jihadi groups, and better detecting those tempted to join at an early stage.

Manuel Valls, the French prime minister, said fighting the appeal of “deadly” doctrines and their "ideology of chaos" was the greatest challenge the country faced in more than 70 years and required a response from all sections of society.

“The radicalisation of part of our youth, seduced by a deadly antisocial model, is in my view the most serious challenge we have faced since the second world war because it deeply damages the republican pact," said Mr Valls, flanked by the interior and justice ministers, as well as those of defence, education, health, culture, youth and sports.

“Radicalisation and terrorism are linked. We are faced with a stubborn phenomenon that has widely spread through society and which threatens it because it could expand massively,” he warned.