Easy does it: Trescothick has been in encouraging form for Somerset, but will play no part for England during their winter tours © Getty Images

Marcus Trescothick has declared himself unavailable for September's Twenty20 World Championship in South Africa as well as England's winter tours of Sri Lanka and New Zealand.

Trescothick hasn't played for England since pulling out of the Ashes tour of Australia last November with a recurrence of the stress-related illness which dogged him throughout last year. And although he said two weeks ago was "delighted to be named in the [Twenty20] squad", he insists he has not yet sufficiently recovered to give England his all - in South Africa for the Twenty20 World Championship, or for England's other two tours.

"Whilst I have been enjoying my cricket for Somerset this summer and feel that I am making good progress, I need to ensure that I am completely ready for a return to international cricket before making myself available for selection," Trescothick said. "I recently informed the selectors that I was happy to be included in the 30-man squad for the Twenty20 World Cup to leave all options open but I am now clear that I should take more time to complete my recovery. I still have ambitions to play for England."

The Twenty20 World Championship had appeared to be the perfect halfway house for Trescothick's comeback. Such a short tournament it would, as Trescothick himself admitted two weeks ago, have acted "as a way of testing myself in an international environment abroad". And though disappointed, the England chairman of selectors, David Graveney, insists that Trescothick has made the right decision.

"The selectors have been acutely conscious that it would be counter-productive to try to rush Marcus back into international action before he was ready," Graveney said. "We appreciate the fact that Marcus has alerted us at the earliest opportunity of his decision which will avoid there being any disruption to the team's one-day planning processes.

"Marcus has proved himself to be a very special talent on the international stage and we look forward to his making himself available again for England when the time is right and to his pushing his case for selection through his performances for Somerset."