Ekaterina Zaharieva is identified as one of the five European Commissioner nominees facing significant scrutiny, according to Politico. Zaharieva, recently nominated by European Commission President Ursula von der Leyen for the role of Commissioner for Startups, Research, and Innovation, is under particular scrutiny. Politico cites her as a notable target, referencing previous concerns about her involvement in a scandal related to the issuance of Bulgarian passports for bribes during her tenure as Minister of Justice, as reported by Euractiv in 2018.

At the top of the list of vulnerable nominees is Oliver Varhelyi from Hungary, known for his controversial tenure as European Commissioner for Enlargement and European Neighborhood Policy. Varhelyi, who is slated to oversee animal health and welfare, is anticipated to face a tough confirmation hearing by MEPs due to his past criticism of EU candidates with rule of law issues and his derogatory remarks about MEPs.

Slovenian nominee Marta Kos, labeled as an "ambassador in disgrace," is expected to face intense questioning about her past. Kos resigned from her ambassadorial posts in Germany and Switzerland in 2020 amid allegations of abuse, and was subsequently investigated by the Foreign Office. Her past role as an advisor at Kreab, a lobbying firm not listed in the EU Transparency Register, and accusations of connections with the former Yugoslav police further complicate her candidacy.

Hadja Lahbib from Belgium is another nominee likely to face scrutiny. Her past, including a controversial trip to Crimea funded by Russia and issues surrounding visa issuance for Iranian officials, may raise concerns during her confirmation process.

Lastly, Maltese nominee Glenn Micallef, who is proposed for the role of Commissioner for Culture, Youth, and Sports, has surprised many with his lack of experience. Micallef, the former chief of staff to Maltese Prime Minister Robert Abela, is expected to face questions about his readiness for the role.