The Pakistan Cricket Board has abruptly revoked No-Objection Certificates given to 13 players currently in England and the West Indies and has asked them to return home to fulfill national and domestic commitments.

The board had originally given as many as 10 players, including seven centrally contracted cricketers, permission to play the entire Caribbean Premier League - which began on August 4 and runs until September 9. Three cricketers without central contracts - Kamran Akmal, Sohail Tanvir and Mohammad Sami - have also been asked to return after they were selected by Rawalpindi, Faisalabad and Lahore Whites for the National T20 Cup. While there is no contractual compulsion on them to do so, it is expected that they will.

Pakistan players called back From the CPL: Imad Wasim, Shoaib Malik, Shadab Khan, Hasan Ali, Mohammad Hafeez, Wahab Riaz, Babar Azam, Mohammad Sami, Sohail Tanvir, Kamran Akmal From England: Sarfraz Ahmed, Fakhar Zaman, Mohammad Amir

The same notices went out to Mohammad Amir, who was to stay with Essex until September, Sarfraz Ahmed, who was to play five games for Yorkshire in the Natwest T20 Blast, and Fakhar Zaman, who was set to join Somerset until the end of the season.

Essex are currently top of Division One of the Championship, after Amir's ten-wicket haul helped them to a two-day win over Yorkshire earlier this week. They are understood to be in negotiations with the PCB about when Amir is required to return, but could try to bring back New Zealand quick Neil Wagner, who filled the overseas spot in the first half of the season, as a replacement.

"The centrally contracted players were given permission to participate in the CPL and English county season subject to recall if the World XI series took place in mid-September," the PCB said in a statement. "So they are being recalled owing to the changes in the schedule brought about due to the change in the original plan of the World XI's tour of Pakistan."

The World XI's visit - subject to security clearance - was originally scheduled for the last week of September but it has been brought forward into a window between September 10 and 16. This change was made to ensure the series would not clash with a high profile by-election in Lahore on September 17, coming in the wake of the Nawaz Sharif's disqualification from the post of Prime Minister last month.

However, the final call over the World XI matches is expected to be taken by the government. The Law and Order Committee of Punjab has reviewed the PCB's request to host the series in Lahore and, according to Najam Sethi, the new chairman of the board, both parties are in agreement over dates and are waiting for the approval of the chief minister.

Pakistan are also set to travel to the UAE from September 21 for a full series against Sri Lanka. Amid this tight schedule, the PCB announced a National T20 Championship running from August 25 to September 10.

"Owing to the late finalisation and rescheduling of the ICC World XI series to be played mid-September, the PCB has been obliged to schedule its National T20 Cup to start near the end of August and finish before the World XI series so that its national team can leave for UAE to play Sri Lanka starting September 24," the PCB explained. "This has compelled the PCB to call back centrally contracted players in contention for selection for the World XI series next month from their ongoing Caribbean Premier League and English county stints.

"The series has been brought forward to mid-September because the Punjab government wants it to be held before the NA120 election on September 17. It can't be held after September 17 because there is no time to both hold the series and also give coach Mickey Arthur time for training his team before the series against Sri Lanka starts on September 24. The players have been asked to report for a pre-series fitness testing/training camp, as planned by the national team management and the National T20 tournament that starts in Multan on August 25."

The returning players have been asked to report to the National Cricket Academy for fitness and medical tests under Arthur's supervision on August 22.