Tributes flow following Graeme Swann's shock retirement

Tributes flowed for England spinner Graeme Swann after his bombshell retirement from international cricket on Sunday midway through the Ashes series.

Swann explained his shock decision in press conference in Melbourne on Sunday, telling reporters England's 150-run defeat in last week's Perth Test -- which gave Australia a 3-0 series lead and the Ashes for the first time since 2009 -- had sealed his decision.

His retirement, effective immediately, comes days before the fourth Test as a rattled England side try to stave off a 5-0 clean sweep in the series.

Australia and England players, plus former greats, said they were stunned by Swann's decision.

"I don't know what to say, I thought he'd bowled OK in the series, just without luck I guess," said fast-bowler Ryan Harris.

"Something's obviously not quite right with him, or he's fulfilled whatever he wanted to do, but to me that's a huge shock."

Spinner Nathan Lyon said he had been "pretty shocked" by the news.

"He's someone who I've looked up to a lot," Lyon said.

"His career stats stand for themselves, he's been an unbelievable spinner and someone who I watched pretty closely in my time.

"I'm sure he will be sorely missed in the England team but I wish him all the best in the future."

Swann's England team-mates took to Twitter to bid farewell to a player they described as one of the greats.

"Congrats @swannyg66 on brilliant career, will miss playing with the fellow twin.. #spintwins," wrote Monty Panesar.

"What a career Swanny has had, very sad to see him retire, great bloke, won a lot of games for England and one of the funniest around," added rising England star Ben Stokes.

Tim Bresnan offered his "huge congratulations on a great career in cricket" and said he would miss the jovial and popular Swann's "constant putdowns and abuse of my mental capacity".

"Also, many batsmen around the world have just exhaled a huge sigh of relief. Due to your constant challenge of the stumps and prodigious spin," Bresnan said.

Former England skipper Michael Vaughan said on Twitter he believed it was "too soon" for Swann to call it a day, describing him as "finger spin out of the top draw".

"Of all the England players over the last 20 yrs he is the one the team (will) miss the most .. Spinners of his quality are a rare breed..." Vaughan tweeted.

"He has also been a brilliant character who plays the game how it should be played .. With a energy of fun and humour.. #OldSchool"

Vaughan said Swann's departure reinforced that "this Ashes tour is a absolute Disaster", lamenting that "just 4 weeks ago England were favourites to win this series".

But he defended Swann from accusations of selfishness, saying he had "made the right call for the team" knowing he wouldn't make it to the 2015 World Cup.