A year ago he was part of Juppe's unsuccessful campaign team in The Republicans' primaries, and then joined the presidential campaign of Francois Fillon, the party's nominee.
"In the past, the subject of treaty change was a French taboo".
But with Germany's economy, Europe's largest, outperforming that of France, the traditional Franco-German motor at the heart of the European Union has begun to misfire. His appointment marks a milestone in the rebuilding of France's political landscape, which has been dynamited by the election of Macron - the first president of modern France not from the country's mainstream left or right parties. According to Bloomberg, Philippe was an ally of Alain Juppé, a former prime minister who came in second to Fillon in the Republican primaries.
Amid deep-seated suspicions that Mr Trump would have preferred Mr Macron's far-right rival Marine Le Pen to emerge victorious from last week's election, senior United States administration officials told AFP that Mr Trump will meet Mr Macron on 25 May in Brussels and "compare perspectives".
The new government is expected to be half women, and with about half the number of ministers former president Francois Hollande's cabinet had.
If En Marche! doesn't gain enough seats, or recruit enough politicians willing to form a coalition, the body can vote out Philippe and install a new prime minister - a move that would likely eliminate any chance Macron has of enacting his agenda.More news: UK police say Assange still faces arrest
"This is the sacred alliance of the old right and left, united in their wish to remain in place at any price", Le Pen said in a statement. One of them, the party leader's niece, Marion Marechal-Le Pen, a rising star representing the party's conservative flank in the south, announced last week that she was leaving politics, at least temporarily.
By appointing Philippe, Macron has passed over some loyal followers including Richard Ferrand, a former Socialist who was one of the first to join Macron's cause a year ago and is secretary general of REM.
The National Front has had only two lawmakers in the National Assembly. But Macron could also be anticipating a Republican wave, and hoping Philippe might still be a palatable choice as prime minister.
Mr Macron added, however, that "what I know is that we have investments to make (in Europe), and so we have to work on investment mechanisms for the future". "Don't give full powers to Mr. Macron and his prime minister". Macron previously met Merkel when he visited Berlin in March as a candidate.
The election of Emmanuel Macron as French president opens up the possibility of generating more dynamism in the European project, German Chancellor Angela Merkel said ahead of a meeting with Macron later on Monday.
Germany is keen to continue with the Franco-German diplomatic drive to keep a lid on the situation in Ukraine.