MELBOURNE - England spinner Graeme Swann announced his retirement from international and first-class cricket with immediate effect on Sunday, in a bombshell just days before the beleaguered tourists meet Australia in the fourth Ashes Test. Swann, who took 255 wickets in 60 Tests in just five years and is sixth on the list of Test wicket-takers for England, said defeat in Perth last week, where Australia sealed the Ashes, had cemented his decision to call it a day.

His abrupt announcement further unsettles England, who trail 3-0 in the series after three heavy defeats and are battling to avoid a humiliating 5-0 series whitewash. "I know I'm making a decision for the right reasons. I made the decision after the Perth Test. It was probably halfway through that Perth game, to be honest," Swann, 34, told a press conference in Melbourne.

"My body doesn't like playing long forms of cricket, my arm doesn't cope with bowling 30-40 overs in the first innings and then repeating it in the second innings a day later. I could feel my performances tapering off to the back-end of games and I wasn't happy with that. As a spinner, that's when you need to come into your own. I am not willing just to hang on and just get by, by being a bit-part player. I want to win matches for England and I don't feel like I was doing that in the second innings any more. As a result, it's time to go."

The off-spinner, a jovial and popular character within the England team, has been under pressure to keep his place in the squad after taking just seven wickets at an average of 80.00 in the three Tests in Australia. Swann, a key member of the English team that won the previous three Ashes series, will miss the fourth Test starting in Melbourne on Thursday and the final Test in Sydney, with fellow spinner Monty Panesar likely to take his place for the Boxing Day Test.

Swann's withdrawal means further disruption for England following the departure of batsman Jonathan Trott earlier in the tour with a stress-related illness. "With two games to go in Australia and then a fiercely competitive summer against Sri Lanka and India, I feel that it is a great time for someone else to strap themselves in and hopefully enjoy the ride as much as I have," Swann said.

"It was very difficult decision. This England team has been my family for the best part of a decade now, and you spend so much time with guys you absolutely love to pieces. There are things I will genuinely miss and I am nervous about that, but to carry on just for those reasons would be really selfish and I'm not prepared to do that."

Swann said in hindsight he could have retired after the previous Ashes series in England earlier this year. "Why didn't I stop then? I knew more or less that the time was coming up," he said. "But I'd never forgive myself -- we had the chance to potentially come out here and win four Ashes series on the bounce."

Swann, who made his Test debut in 2008 and averaged 29.96 with the ball, said his decision had nothing to do with uproar over comments he made on Facebook last week that likened the third Ashes Test loss to being "raped". "It was unfortunate that someone chose to trawl through my brother's Facebook page. I did apologise for that and it had nothing to do with it," Swann said.

England team director Andy Flower said Swann had played a major role in England's recent success. "Graeme Swann has made an outstanding contribution to the England cricket team in all formats throughout an incredibly successful career, and I would like to congratulate him on all that he has achieved," Flower said in a statement. "His commitment, competitive spirit and sense of humour have been recognised and admired by team mates and supporters alike, and he has played a big part in England's success over the last five years. "The dressing room will be a very different place without Graeme's unique personality and I would like to wish him all the very best for the future."

Meanwhile, former England stars Michael Vaughan and Geoffrey Boycott expressed their admiration for spin bowler Graeme Swann on Sunday after he abruptly announced his retirement from the sport. Swann, 34, bows out with immediate effect, meaning he will play no part in the final two Tests of the Ashes tour of Australia, when England will bid to restore pride after going 3-0 down and surrendering the urn.

Former England bowler Derek Pringle criticised the timing of Swann's decision, writing on Twitter that the off-spinner "should have seen the tour out as a senior player". However, former captain Vaughan said that Swann's recent struggles with an elbow problem, which has seen him undergo three operations, suggested that he had reached the point of no return.

"There will be many cricket fans who have travelled over saying, 'Wait a minute, you signed up to play the whole of the Ashes tour yet you're doing one three games in,'" Vaughan told BBC Radio 5 Live. "But I think it's more the mind. I think the elbow problem has just triggered the mind to suggest that enough's enough."

Vaughan admitted that he was "surprised" by Swann's timing, but dismissed the suggestion that his former team-mate had put himself before the team. Those that say he's being selfish, must take into consideration that he's giving up an England contract of nine months that is a lot of money, so he's throwing a lot of money away by making the decision now," Vaughan said. "I don't think he's been selfish. I think he's done it for his own mind. He thinks the team are better off without him."

Former opener Boycott praised Swann's honesty for admitting that he was past his best. "He hasn't been right the whole series, he hasn't been the Graeme Swann we know," Boycott said. "He's better than his figures. I think it's very honest. It's very difficult to get up for top-class sport when you're not bowling your best. I think it's very honest to say, 'Hey I've shot it, that's it, I'm not going to be any good anymore.' It takes a brave man to do that."

Boycott added: "He's nothing to be ashamed about, he's nothing to be embarrassed about. He's been an excellent performer for England and I think he can hold his head up high." With 255 Test victims to his name, Swann is his country's most successful off-spinner and former England coach David Lloyd praised his dedication to the team ethic.

Writing on Twitter, Lloyd said: "Swann retirement... Been a brilliant bowler in International cricket. Not about individual records for him." Meanwhile, Mike Newell, director of cricket at Swann's county Nottinghamshire, said Swann's reputation as a joker belied a meticulous approach to his profession.

"He joined us with a reputation for not taking things seriously, but I found him to be very thoughtful about his cricket and very committed to improving his game," Newell told the Nottinghamshire website. "Swanny has been a dominant performer in Test cricket for six years and it will leave a huge gap in the England team because there is no outstanding spinner quite ready to fill the place that he will leave."