England are among four countries to give warning that weakened teams may be sent to the ICC Champions Trophy in September unless the tournament is shifted from Pakistan. A final decision on the venue is scheduled to be made by tele- conference this week, but Australia, New Zealand and South Africa share concerns about safety.

David Collier, the ECB chief executive, was in Dubai yesterday for a four-hour briefing on safety and security from Nicholls Steyn & Associates, the ICC's consultants, after which a spokesman for the governing body said: “Until or unless the [ICC] board decides otherwise, the tournament will proceed in Pakistan.” Australia players, including Ricky Ponting, Michael Clarke and Andrew Symonds, along with Jacob Oram of New Zealand, have expressed reluctance to play in Pakistan and the ECB has said that it cannot guarantee the participation of all its players in the tournament after recent bombings in Karachi and Islamabad.

Advice from the British Foreign Office about Pakistan, which is displayed on its website, reads: “There is a high threat from terrorism and sectarian violence throughout Pakistan.” Among the cities with a “heightened threat to Westerners” are the venues of Rawalpindi, Karachi and Lahore.

England players will be briefed by the Professional Cricketers' Association before the start of the third Test against South Africa at Edgbaston on Wednesday week. Sri Lanka is the designated back-up venue, but switching to Colombo, where there are also security concerns, may create apprehension and South Africa and England have been mooted as potential alternatives.

Reports from India say that the ICC is aware of a “credible external threat” to the competition and an ICC statement acknowledged that, while the Pakistan Cricket Board (PCB) provided a high level of security during the Asia Cup, which finished this month, concerns have been expressed about “potential for threats beyond the PCB's control”.

If one of the concerned boards calls for a vote, seven of the ten full members - including Bangladesh and Zimbabwe, who are not involved in the eight-team event - must back a switch. As ever in the world of ICC politics, the position of the Asian bloc will be central to the outcome.

But the danger for the credibility of a competition that has never captured the public imagination in a way that its unofficial billing as a mini World Cup suggests is that countries who feel uneasy in Pakistan will either pull out or give players the option to withdraw.

Tim May, the chief executive of the Federation of International Cricketers' Associations, and representatives of ESPN Star Sports, the broadcaster, were also present at the briefing. It is understood that the television company wants a decision sooner rather than later for practical reasons.

A possible compromise would be to move matches from Karachi, thought to be the most dangerous location, to Lahore and Rawalpindi. After much internal debate, England agreed to play in Karachi in 2005 only on condition of the highest level of security. As recently as four months ago, Australia postponed their whole tour.

Haroon Lorgat, the newly appointed ICC chief executive, said: “If it was up to the player representatives, they would prefer not to be in Pakistan. They have concerns because no guarantee on safety and security can be given by the PCB, the ICC or the security consultants.”

Board representatives were told yesterday that Karachi would be a safe venue only if security levels matched those at the Asia Cup final. On that occasion, they were especially tight because of the presence of Pervez Musharraf, the President of the country. The report did not consider the preparedness of Lahore or Rawalpindi.