Emmanuel Macron, 39, ploughed ahead with his plans for further EU integration with the introduction of Brussels army and shared defence budget during a much-anticipated speech on Tuesday.
But his suspected power grab was all while Mrs Merkel attempts to form a government following a dismal election victory over the weekend.
And in signs cracks could begin to engulf the Franco-German partnership, Angela Merkel’s spokesman said it was “too early for a detailed assessment” after Mr Macron’s delivered his plans.
Instead Steffen Seibert said Mrs Merkel would look at his proposals for the further amalgamation of the bloc with an “open mind”.
He said: “The Chancellor welcomes the fact that the French President spoke with so much verve, with so much European passion, and that he presented a lot of substance for the upcoming and essential debate about the future of Europe.”
It comes after Mr Macron’s presidential victory earlier this year marked the rebirth of the Franco-German power base as both countries looked to reassert their authority as the driving force of the Brussels club after Brexit.
And it was believed Mrs Merkel had set her sights on Paris as her number one partner to help her secure Europe’s future.
But last weekend’s German elections could further dent this alliance with Mr Macron delivering a speech on European Union reform as he attempts to rise from a humiliating fall from grace after he rose to power as the EU’s golden boy.
Mr Macron campaigned on a bid to “relaunch” Europe alongside Germany, but Mrs Merkel’s disappointing election result and the pledge of former coalition partners the SDP to go into opposition, leaves her with less room to manoeuvre.
And Mr Macron seized the opportunity to lay out his ambitious plans for the bloc and the eurozone while Mrs Merkel was otherwise occupied.
The German Chancellor could also be forced to form a government with the FDP, whose leader Christian Lindner considers Mr Macron’s calls for a eurozone budget as a “red line”.
Mr Linder said German money should not be used for “French public spending or fixing Berlusconi’s mistakes” in Italy.
And, speaking after the election, a weakened Mrs Merkel also appeared lukewarm.
She said: “I‘m not going to rule out anything or set red lines. The Union will support what makes sense.
“My view is that we can use more Europe, but this has to lead to more competitiveness, more jobs and more clout for the European Union.”