Valls reputation as a Socialist Party right-winger - he talked tough on Roma, immigration and crime while interior minister and called for the party to change its name and water down its biggest ever reform, the 35-hour working week, while in opposition - has already meant that the Green party, EELV, has refused to join his government.
It may also mean that the Greens may not vote confidence in the government when he presents his policies next Tuesday, although EELV MPs are likely to be split on that decision and a majority could vote for.
The hard-left Left Front, which includes the Communist Party, has already said it won't back the confidence vote, although that's not new since its MPs didn't back Jean-Marc Ayrault's government when it was formed, either.
There are even threats to abstain from the Socialist Party's left wing but the government is not believed to be in any danger since doing so would mean being expelled from the party's parliamentary group and probably being deprived of the party's endorsement at the next election.
Valls has moved to head off a revolt by appointing two figures identified with the left, Arnaud Montebourg and Benoît Hamon, to important posts - Hamon to education, where he replaces Vincent Peillon whose reform of school hours raised some parents' hackles, and Montebourg, whose headline-catching post of industrial renewal czar has been beefed up to include the economy as a whole.
Montebourg remains subordinate to the finance minister, now Michel Sapin, stepping into Pierre Moscovici's shoes.
In promoting Montebourg, Valls clearly hopes to outmanoeuvre the only minister who rivals him in the opinion polls, sharing the same image of a young, outspoken and dynamic iconoclast, even if Montebourg was regarded as left-wing during 2011's Socialist primaries while Valls was seen as the most right-wing candidate and suffered accordingly winning only 5.65 per cent of the votes compared to 17 per cent.
As a minister Montebourg has proved more nationalist than leftist and, after a bumpy start, his relations with big business have taken a turn for the better, top bosses such as Vivendi's Vincent Bolloré and Véolia's Antoine Frérot praising him for his can-do attitude and defence of French industry.
Relations with his Socialist comrades have often been less harmonious.
Ayrault is said to detest him after the two fell out in public over the closure of a blast furnace at the Florange steelworks and Moscovici had several run-ins with him.
Right-wing opposition leader Jean-François Copé, who inevitably declared himself "very worried" by the make-up of the new government, picked out Montebourg, along with the supposedly soft-on-crime Justice Minister Christiane Taubira, for special criticism.
"It's him who will go and discuss our economic policy in Europe, especially with the Germans, who he has copiously insulted for two years," he commented.
Montebourg last year called for a confrontation with Germany over Chancellor Angela Merkel's austerity policies and was less than polite about the European Commission in an interview with Le Monde magazine.
Brussels will be taking a close look at Sapin, too, since he has to carry out Hollande's promise to reduce the public deficit to 3.0 per cent of GDP in 2015 with France already behind target at 4.3 per cent at the end of 2013 when it was supposed to have been at 4.1 per cent.
He and Montebourg will preside over 50 billion euros of cuts as part of Hollande's Responsibility Pact, a deal that has aroused opposition on the left and a luke-warm welcome from employers.
Sapin was promoted from labour despite having failed to keep the president's promise to reverse the upward trend in unemployment and probably owes his ascension to the fact that he is one of Hollande's long-term allies, a faction that is reported ot have met on Tuesday night to express their discontent at the reshuffle.
Royal, the party's unsuccessful presidential candidate in 2007, is widely believed to be being rewarded for sticking by Hollande during the presidential election despite their break-up and his now-defunct relationship with Valérie Trierweiler.
She is one of only two new ministers, the other being the new labour minister, François Rebsamen, the leader of the Socialist group in the Senate and another Hollande ally, who refused to join the Ayrault government because he was not offered the interior ministry.
Left-wing or not, the new ministers are not exactly on their uppers.
Only three - Vallaud-Belkacem, Hamon and Bernard Cazeneuve - have declared assets of less than 200,000 euros, while three - Montebourg, Jean-Yves Le Drian and Marylise Lebranchu - are worth between 500,000 and one million euros.