England remain hopeful they will welcome back Andrew Flintoff to their ranks before the end of the summer following an exploratory operation on his troublesome left ankle yesterday.

The 29-year-old all-rounder has been sidelined with ankle problems since before the first Test of the summer against West Indies at Lord's and underwent an exploratory arthroscopy to determine the extent of the injury.

It was feared Flintoff might be ruled out for the whole of the summer, Peter Moores' first as England coach, but the operation was described as ''routine'' by the England and Wales Cricket Board medical staff. In a statement issued yesterday, they confirmed: ''Early signs are that the operation was routine and Andrew will begin his rehabilitation accordingly following successful removal of tissue contributing to anterior impingement in the ankle.

''Andrew will require a programme of strengthening and proprioceptive work before he can start to return to training and bowling. It is anticipated that he will aim to return to playing cricket before the end of the summer.''

That prospect will boost Flintoff and England, who have lacked penetration without their most consistent bowler in the opening two Tests against West Indies.

It is the third operation Flintoff has had on the same ankle in three years, the last one taking place last summer, which sidelined him for three months and he only just made it back in time to lead England to the Champions Trophy and their disastrous Ashes tour.

But throughout the winter Flintoff felt some discomfort in the ankle, which swelled up again during Lancashire's championship match against Hampshire at the Rose Bowl shortly before the opening Test.

He was named in the squad for the second Test at Headingley, which England won by an innings and 283 runs without him, but once again was unable to prove his fitness when he tried to bowl in the nets.

Flintoff had hoped to finally shrug off the injury and feature for Lancashire in the current championship match against Sussex at Hove, only to be ruled out again and booked in for yesterday's exploratory operation.

The current problem is believed to be separate from the bone spur problem he suffered last year, but he now faces a race against time if he is to feature for England this summer.

With the Test series against India, which begins at Lord's on July 19 and finishes at the Oval on August 9, less than ten weeks away, the seven-match one-day series against them, starting at the Rose Bowl on August 21, may be a more realistic comeback date.

Should he recover in time, Flintoff will then depart with the rest of the squad for the Twenty20 World Cup in South Africa and one-day and Test series in Sri Lanka before Christmas. He has fought back from a similar problem twice before in his career and said this week: ''I know how much work is ahead of me, but I'm desperate to get back playing for England as soon as possible.''