World champions Australia could play an extra game in England this autumn after threatening to cancel their scheduled Vancouver Test match against Canada.

Crisis-hit Canadian rugby has seen its top 60 players go on strike following coach Dave Clark's controversial sacking last month.

Ian Birtwell, who masterminded Canada's 1991 World Cup campaign when they reached the quarter-finals, is now in charge for appointments with Australia (October 27), Scotland (November 18) and Ireland (November 24).

Birtwell has written to the players - who want Clark reinstated - pleading for their support, yet Australian Rugby Union managing director John O'Neill is rapidly running out of patience.

The Wallabies are due to face Canada, Spain, England, France and Wales on tour, but O'Neill says the ARU has already spoken with English rugby bosses about an alternative late-October fixture should they ditch their Vancouver plans.

"We are giving them (Rugby Canada) until the end of the week to give us an iron-clad guarantee that it will be their best team, otherwise we will probably have to cancel that leg of the tour," O'Neill said.

"I keep being told that I have been sent a letter, but I haven't received it yet.

"There is really no point in us going there unless there is a competitive team to play against.

"If we went over there, played a third or fourth string Canadian team and beat them 100-blot or something, then in a cost-benefit sense, it is just not worth our while," O'Neill told the official ARU website.

Whether the Rugby Football Union could accommodate Australia though, is debatable, given that England's top clubs have important Heineken Cup and European Shield matches scheduled on the last weekend of October.