This is largely opinion, but we can examine the legitimacy of Zelensky's administration based on available evidence.
Zelensky's continued tenure in office was officially affirmed by a resolution approved by 268 members of the Ukrainian Parliament in February 2025 (by unanimous vote, though 12 members were absent), as reported by Al Jazeera.
The Zelensky administration also maintains strong public support. The Center for East European and International Studies reports:
"Although the initial 'rally 'round the flag' effect from 2022 – which sent support for Zelensky soaring as high as 85 per cent by July 2023 – has abated somewhat over the years, his approval is still very high. Indeed, our latest survey in January 2025 found a further slight uptick in Zelensky's approval ratings to 63 per cent ('fully/somewhat approve')."
Additionally, 400 NGOs signed a petition declaring elections impossible without sustainable peace. According to Reuters, this sentiment was echoed by Ukrainian opposition figures, including former Prime Minister Yulia Tymoshenko, who stated that Zelensky remained Ukraine's legitimate leader until someone else was elected. She called holding elections during wartime "impossible and immoral," noting that military personnel would be unable to participate.
All of this suggests that it is false to claim that Zelensky's administration is not sanctioned by either Ukraine's legislative body or its citizenry.