Four of Fifa’s leading sponsors – Coca-Cola, McDonald’s, Visa and Budweiser – have demanded that its embattled president, Sepp Blatter, step down immediately in the face of a continuing corruption crisis. The dramatic intervention on Friday night from four of Fifa’s biggest backers hugely increases the pressure on the 79-year-old after Swiss prosecutors last week opened criminal proceedings against him. The four American companies have been under pressure themselves to take a stand since May, when the US Department of Justice alleged a “World Cup of fraud” and charged 14 people, including nine current or former football officials, with money laundering, racketeering and other offences...