Jason Gillespie takes cover at Lord's in London, where the Australians were given a security briefing © Getty Images

A third London bombing would force Jason Gillespie to consider pulling out of the Ashes Tour after admitting "a lot of guys are nervous" about the terror threats. Gillespie last night told a Melbourne radio station "there would be serious questions" about the tour continuing if there was another blast.

"It is very difficult to say, but I would consider it [withdrawing] if another went off," he told 3AW. "I can't speak for anyone else. If something else did happen I would think about it personally, yes."

Following a series of explosions in London on July 7 and 21, Cricket Australia said the security of its players was the top priority, and Paul Marsh, the Australian Cricketers' Association chief executive, told the Courier-Mail he was confident with the advice. But Marsh said he "would have to consider things if another bomb goes off".

While the Australians were in London for the first Test police searched a bus and evacuated the area outside their hotel, and the players were told not to catch underground trains. The Sydney Morning Herald reported that during a security briefing one player said if similar incidents had occurred in a country such as Pakistan there would be a push to end the trip. There is little doubt that if the team had been in a third world country the explosions would have forced them home.

"If another bomb went off in England there would be serious questions asked about the tour," Gillespie said. "I know a lot of the guys are nervous. My wife is over here. A lot of guys have their wives and families here. It is not so much us, but them as well."

Security has been stepped up at Edgbaston ahead of the second Ashes Test starting on Thursday. The Warwickshire CCC authorities said sniffer dogs would be deployed to check delivery vehicles, while all spectators would be searched when entering the ground.