LONDON — Cristiano Ronaldo led tributes to Alex Ferguson from the worlds of sport and politics Wednesday after the Manchester United manager announced he was standing down at the end of the season. Former United winger Ronaldo's message on Twitter was simple — he posted a picture of his first day at Old Trafford with Ferguson in 2003 with the message “Thanks for everything, Boss.” British Prime Minister David Cameron, a supporter of Premier League strugglers Aston Villa, tweeted: “Sir Alex Ferguson's achievement at#MUFC has been exceptional. Hopefully his retirement will make life a little easier for my team.” FIFA president Sepp Blatter said the football world may never again see a reign like Ferguson's at United that spanned 26 years and 38 trophies, including 13 Premier League titles. “His achievements in the game place him without doubt as one of the ‘greats'” Blatter said on Twitter. “Will his longevity at the top ever be repeated?“ UEFA President Michel Platini hailed Ferguson as “a true visionary” who has made “a major contribution” to football. “His CV is almost unique in a profession where results count and which normally looks to short-term rather than long-term solutions,” Platini said. “His dedication, his attention to details and his eye for talent while manager of Manchester United and Aberdeen have been richly rewarded for over 30 years.” While former Manchester United players hailed the manager's extraordinary record of winning trophies, ex-midfielder Paul Ince warned that his successor would find Ferguson's shadow looming over them in his new role on the club's board. David Beckham paid tribute to “father figure.” Former England captain Beckham, one of ‘Fergie's fledglings', a crop of young players that the Scottish manager brought through the Old Trafford youth system and into the first team, wrote on his Facebook page: “As I have said many times before the boss wasn't just the greatest and best manager I ever played under he was also a father figure to me from the moment I arrived at the club at the age of 11 until the day I left. “Without him I would never have achieved what I have done in my career. He understood how important it was to play for your country and he knew how much it meant to me,” added Beckham, now with French giants Paris St Germain. “Thank you boss and enjoy the rest!“ Peter Schmeichel, the Danish goalkeeper who was one of Ferguson's most important signings at United, described his decision to retire as a shock and said he could not “make sense of the timing.” “It has come as a bombshell, I really don't know what to make of it,” Schmeichel said. Michael Owen, the former England striker who was used sparingly by Ferguson in two seasons at United, said he was honoured to have played under him. “What a man and great that it has ended on his terms. What a privilege to have played under arguably the best manager the world has ever seen. His record will surely never be eclipsed,” Owen said. Louis Saha, the French striker who scored 42 goals in 120 appearances for United said Ferguson was “the most powerful man I ever met in my life after my dad,” adding: “Huge respect for Football God.” And golf star Rory McIlroy wrote: “An end of an era today! Sir Alex Ferguson, the greatest of all time! United will have a tough time trying to replace him!“ Bobby Charlton, a member of Busby's side that won the European Cup in 1968 and still a director, said United's dominance of the English game was solely down to Ferguson. “I am a director but I hardly do anything because we are winning all the time and it is all down to Alex Ferguson,” Charlton said. — Agencies