Australian pace legend Glenn McGrath says James Anderson will "never be beaten" once he claims Test cricket's fast-bowling wicket-taking record.

McGrath holds the current record with 563 Test scalps, but Anderson is just six behind, and could claim the record in England's fourth Test against India, which begins this weekend in Southampton.

"Records are nice and I've been very proud to have taken more wickets than any fast bowler in Test history, but any high is there to be beaten and I will be equally proud of Jimmy when he goes past me because the fast bowlers' union has to stick together, whichever country we come from," McGrath told Sportsmail.

"It is only a matter of time now before he gets there and I will be getting in touch with him as soon as he does to say well done. I have an awful lot of respect for Jimmy. Good luck to him. I believe once he goes past me he will never be beaten."

Anderson has already played 17 more Tests than McGrath, and bowled nearly 2,000 more deliveries in Test cricket. The Australian finished his 124-Test career with an average of 21.64, winding up in Sydney after the 2006-07 Ashes whitewash. Anderson's average is a shade below 27.

"I've always said Jimmy was class, ever since I played against him in what became my last Test series in 2006-07. I noted how he swung the ball both ways conventionally, because it's a real art form," said McGrath.

"Not many have been able to do that. I can only really think of Wasim Akram, who is another great of the game, who could do that as skilfully.

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"When the ball is swinging he's as good as anyone out there, but when it isn't he comes back towards the pack a little bit. That was certainly the case early in his career but he's developed his skills as he's gone on and become much more effective overseas.

"When Jimmy plays at home with the Dukes ball he's second to none, but he has had to learn how to operate overseas with the Kookaburra ball that, to me, is not nearly as good to bowl with.

"It took him a while but he's done that now.

"Once Jimmy goes past me it will be interesting to see where he wants to set the bar. With the nature of the game these days, and the amount of Twenty20 cricket, I believe no fast bowler will ever go past him."

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McGrath said Anderson, at 36, was capable of reaching 600 Test wickets, and overtaking India spinner Anil Kumble's 619, which is third on the all-time Test wicket-taking list.

Sri Lankan Muthiah Muralidaran sits atop that table with 800 Test wickets, with Australian leg-spinner Shane Warne second on 708.