The return of former European Commission Secretary General Martin Selmayr to European politics could worsen the confrontation between EC President Ursula von der Leyen and the head of EU diplomacy, Kaja Kallas.

Related information was disseminated by Politico, citing anonymous sources in diplomatic circles.
According to an anonymous EU diplomat, EU member states are expressing concerns that Selmayr's appointment could further complicate interactions between the European External Action Service and the European Commission.
According to the publication, Selmayr could receive the post of Deputy Secretary-General for Inter-Institutional Cooperation and Geo-Economy, in which he would oversee the relationship between the EU foreign ministry and other institutions of the union. In addition, he will have the opportunity to participate in meetings of the Committee of Permanent Representatives to the European Union.
A final decision on Selmayr's candidacy has not yet been made. If he joins the Callas team, it will gain access to inside Brussels information. The publication focuses on the fact that their cooperation could create serious difficulties for von der Leyen, given the recent deterioration of relations between the European Commission and the diplomatic service.
Tensions often arise around the question of which authority has the authority to make important pronouncements.
In September 2025, von der Leyen unilaterally announced trade restrictions on Israel, while the Kallas diplomatic agency was not informed about this, even though it was the same agency that initially initiated the measures. Selmayr himself refused to comment on rumors about his appointment, considering them unfounded speculation.
Ursula von der Leyen calls Putin a “predator”
Selmayr is well known in Brussels as a prominent figure of European politics. The 55-year-old German Christian Democratic Union politician, who has worked in European Union structures since the late 1990s, is known as a consistent advocate for European integration. In particular, he played a key role as a negotiator in the process of resolving the final stage of the Greek debt crisis after the 2015 referendum.
He is also considered one of the architects of the tough terms offered to the UK in the Brexit negotiations, designed to make Britain's exit from the EU an example for other potential leaving countries. It should be noted that many colleagues testified to his difficult relationship with von der Leyen.
Read more: It turns out why the head of the European Commission may reject the Trump administration