Akhtar, who has 165 test and 199 One-day wickets, is struggling to recover from an ankle injury after having undergone a knee operation in Australia in February.
He has not played since January when he pulled out of the home One-dayers against India with the knee problem.
''A medical panel of the board has examined his ankle injury and advised him against heavy training and bowling for next three weeks,'' Director of Cricket Operations Saleem Altaf told.
''The panel found there is heavy swelling around his ankle and he needs a three-week rest at least after which it will decide after another examination if he can resume bowling,'' Altaf said.
He conceded it did not appear possible for Shoaib to recover in time to play from the start of the tour, which starts in the last week of June. The first of four tests against England starts on July 13 at Lord's.
Akhtar, 30, is the top wicket-taker in the current squad and Altaf said the board was also waiting on reports about his injury from specalists in South Africa and Australia.
The Pakistani selectors will announce the touring squad this weekend.
Sources in the board said the PCB officials had developed an issue with Akhtar over his preference to undergo his rehabilitation process with a personal trainer, Dr Tauseef Razzak, instead of the board's appointed South African trainer Grant Compton.
Altaf also confirmed a meeting of the board's ad-hoc committee held yesterday decided to look into the players' demand for an increase in pay.
''A committee will study the financial repercussions but we expect the players will get a pay raise as the committee recognizes their performances,'' Altaf said.
Pakistani players are paid monthly retainers of 200,000 rupees (3350 dollars), 125,000 (2250 dollars) and 75,000 (1250 dollars) in three different categories of central contracts.
Altaf said the players could get a pay raise of between 25 to 30 percent in their annual contracts from July 1.
There are currently 20 players on central contracts.