As the Manchester United manager's resignation and not the Queen's speech threatened to top the news agenda, David Cameron found time to talk football too, tweeting: "Sir Alex Ferguson's achievement at #MUFC has been exceptional. Hopefully his retirement will make life a little easier for my team #AVFC.(Aston Villa)"

Ed Miliband seemed to be delivering a Twitter obituary: "Proud man. Great manager. Staunch Labour Party supporter. Sir Alex Ferguson will never be forgotten." Veteran MP Peter Hain admired the manager's political timing: "Nice timing Alex Ferguson retirement obliterates Govt on Queen Speech he's been #Labour always."

The former deputy prime minister John Prescott tweeted thank you "for helping the reds in football and politics. Legend".

Alastair Campbell, Burnley fan and friend whose interview with Ferguson in the New Statesman in 2009 unveiled the United boss's passion for politics at unusual length, said: "Best manager of all time, great man, bowing out in style, with another trophy on the shelf."

Ferguson has not often been known as a peacemaker in his professional life, but in Northern Ireland, the deputy first minister and United fan, Martin McGuinness described the manager as a "great supporter of our peace process" and advised others "stay strong, remember the good times, AF will remain connected to Man U, get interested in who's coming next!!"

Alex Salmond, Scotland's first minister, was keen to stress Ferguson's earlier success as a managernorth of the border. "What really marks him out as a footballing legend are his achievements at Aberdeen," said Salmond, referring to Ferguson's team that broke the Celtic and Rangers' league and cups hegemony, and won the European Cup Winners' Cup in 1983.

Other high-profile United fans were also in shock. The sprinter Usain Bolt said there were "always words of encouragement even though we were in different sport", while the golfer Rory McIlroy called Ferguson "the greatest of all time! United will have a tough time trying to replace him!"

The actor Dominic Monaghan, known for his roles in The Lord of the Rings trilogy and hit US TV series Lost, tweeted: "Absolute. SHOCK. Reeling from the #fergieretires #fergie news. Most successful football manager of all time. The legend. United march on."

TV presenter Eamonn Holmes, tweeted a reminder of the United manager's incredible ability to seemingly persuade match officials to provide extra time for United to score on those rare occasions they were behind in his brief pen picture. "Sir Alex – how do you follow that? Thanks for the memories, the trophies , the spats, the entertainment, the passion and the chewing gum … but most of all thanks for The Impossible Dream and Fergie Time!"

Within football, Sepp Blatter, president of Fifa, the sport's world governing body, underscored Ferguson's status as "without doubt as one of the 'greats'" and asked "Will his longevity at the top ever be repeated?"

Michel Platini, head of European football's top body Uefa, also hailed Ferguson's staying power. "His CV is almost unique in a results-based profession that normally focuses on short-term solutions rather than long-term vision."

Richard Scudamore, chief executive of the English Premier League said: "Nobody has been a bigger star on our stage. You can't talk about the Premier League without talking about Sir Alex Ferguson. It's a huge gap to fill, a huge role to fill. The legacy he's built there makes it a huge opportunity for whoever takes the job."

While current United players seemed to be keeping quiet on the news, former ones were heaping praise on him. Steve Bruce, who played for nine years at Old Trafford, including as captain, and now manages Hull City, told Sky Sports News: "He's got a humility about him from his working class background where he'll treat the groundsman just as well as he'll treat his star centre-forward. He's got a fantastic humility about him for all he's achieved."

Michael Owen, the former England star who played at United under Ferguson and is retiring as a player at the end of the season, said: "It's just not sinking in! Manchester United with no Sir Alex just doesn't feel right. What a man and great that it has ended on his terms."

Real Madrid and former United forward Cristiano Ronaldo said: "Thanks for everything, Boss."