LONDON — As he prepares to become Switzerland’s economics minister, Guy Parmelin is facing widespread criticism of his skills — in speaking English.

The Federal Council, the Swiss executive body, announced last week that Mr. Parmelin would be the next leader of the Department of Economic Affairs, Education and Research, a job that involves negotiating accords with other countries and with bodies like the European Union.

The news prompted a wave of commentary from news outlets and on social media, much of it mocking — a reflection of how thoroughly English has become the language of international diplomacy and business. Among world leaders, a command of English is often taken for granted, even when translators are present.

Critics recalled what Mr. Parmelin, a former grower of wine grapes, told reporters before he joined the Federal Council in 2015. “I can English understand but…” he said in English, before switching to his native tongue to add, “I prefer responding in French to be more precise.”