A Prison Service source suggested the prison van ambush would probably involve one of the escapees having access to a smuggled mobile phone.
A phone call could then be made or a text sent to let the armed gang know which prison van they were in and so which vehicle to target, among the number of vans making their way from jail to Manchester Crown Court.
More top news
Fans queued overnight to get their hands on the last remaining tickets to see Benedict Cumberbatch in Hamlet
Youth work charity Kids Company is to stop running services from Wednesday evening, it has been reported.
If the high-profile charity does close, its demise will have a huge impact - not only on those it helps but also on its supporters.