Energy infrastructure has been central to the resignation of Portuguese Prime Minister António Costa, as the BBC reports.

After corruption investigators searched Mr Costa’s official residence, Mr Costa resigned, saying that the “dignity of the functions of prime minister is not compatible with any suspicion about his integrity, his good conduct and even less with the suspicion of the practice of any criminal act”. The investigation centres around the awarding of contracts for two lithium mines in the north of the country and hydrogen production and data centre projects in Sines, to the south of Lisbon.

Mr Costa’s chief of staff, Vítor Escária, is one of five people having detention warrants issued to them, while Infrastructure Minister João Galamba has been indicted. According to the Financial Times, nine community organisations opposed to the lithium mines have already called for the environmental approvals for the mines, granted earlier this year, to be cancelled.

Mr Costa’s resignation puts at risk Portugal’s plan to become Europe’s leading producer of lithium, something Europe more widely would have welcomed as it seeks greater energy security.