Opinion of Advocate General Tanchev delivered on 3 June 2021.#European Commission v Tempus Energy Ltd and Tempus Energy Technology Ltd.#Appeal – State aid – Aid scheme – Article 108(2) and (3) TFEU – Regulation (EC) No 659/1999 – Article 4(3) and (4) – Concept of ‘doubts as to the compatibility of a notified measure with the common market’ – Decision not to raise objections – Formal investigation procedure not initiated – Guidelines on State aid for environmental protection and energy 2014-2020 – Code of Best Practice for the conduct of State aid control procedures – ‘Pre-notification’ contacts – Procedural rights of interested parties – Electricity capacity market in the United Kingdom.#Case C-57/19 P.