France's ruling Socialists accused conservative former president Nicolas Sarkozy on Monday of appealing to racist sentiments in criticizing the country's Morocco-born education minister.

Sarkozy, expected by many to run for election in 2017, used no explicitly racist words but came under fire for singling out two non-white female ministers in a largely white government for charges of gross incompetence.

Sarkozy's main target was Najat Vallaud-Belkacem, a young Franco-Moroccan minister in charge of a post-primary schooling reform plan that has irked many teachers and been slammed by many in Sarkozy's UMP opposition party.

UMP chief Sarkozy weighed in at a political rally north of Paris last Monday, saying: "In the unrelenting quest for mediocrity, Najat Vallaud-Belkacem is in the process of overtaking Christiane Taubira."

Taubira is justice minister and was pilloried by political opponents when shepherding a bill through parliament to legalize same-sex marriage in 2013, with some of the invective mocking the racial origin of the French Guiana-born justice minister.

Contacted about the accusation of racism, a UMP official said Sarkozy did not intend to comment.

Regarding the attack on Education Minister Vallaud-Belkacem, Socialist Party head Jean-Christophe Cambadelis accused Sarkozy of resorting to racially-charged rhetoric.

"It's got a certain connotation," Cambadelis told RTL radio. "This attack is slightly xenophobic, I believe."

Several other Socialists joined the riposte against Sarkozy, who ruled from 2007 to 2012. He failed to secure re-election in 2012 when he waged a markedly more right-wing campaign in what many political analysts read as an attempt to appeal more to voters of the anti-immigrant National Front party.

Finance Minister Michel Sapin said it was "no coincidence" that Sarkozy had paired the two ministers in one hurtful phrase: "It's an appeal to the lowest of human instincts."