Just 48 hours before they depart for their Australian tour, and a mere five months before the start of a World Cup that they hold serious ambitions of winning, the sky appears to have fallen in on the England rugby team. Certainly on a team that has Lawrence Dallaglio as its leader.

Dallaglio has seen off some serious opponents in his time, but nothing so daunting as yesterday's front pages. Allegations in the News of the World that the England captain took cocaine and ecstacy with two team-mates at the end of the 1997 Lions tour of South Africa, and suggestions that he once acted as a drug-dealer in west London, inevitably sent shock waves through English rugby yesterday and prompted the Rugby Football Union to launch an urgent investigation.

Dallaglio (26) was due to lead England to Australia on Wednesday for a warm-up tour prior to this autumn's World Cup.

The revelations, if true, blow the coach Clive Woodward's entire plans for the tournament out of the water and will almost certainly see the Wasps flanker suspended from international rugby. The air of shocked dismay hanging over Twickenham yesterday will be matched around the world this week.

Ashley Woolfe, Dallaglio's agent, said last night an imminent statement from the player was unlikely. Either Dallaglio is poised to collect one of the biggest libel awards in history, or the News of the World has torpedoed his wholesome image for good.

Even his "shocked and very surprised" Wasps coach Nigel Melville, himself a former England captain, acknowledged that the story would force the International Board and the RFU to react swiftly. "There is a wider implication for the game as a whole," said Melville.

"He's only one player in a game with lots of young people. We have to look at that issue because if there is a problem we have to deal with it." With the domestic season over and Dallaglio relieved from club duty until after the World Cup, the flanker's England future rather than his Wasps dayjob is under the more immediate threat.

His role as the national captain is surely untenable. How can a governing body or sponsor entertain the hypothetical prospect of a team going into a World Cup led by an ex-drug dealer?

Peter Wheeler, the chief executive of Premiership champions Leicester and another former England captain, said: "If the reports of Lawrence's conduct are accurate it must put his position as captain in jeopardy. Lawrence is a role model and, in that situation, you cannot become involved in the activities that are alleged."

There remains plenty of backing inside the England squad, who tend to view recent incidents such as Jeremy Guscott's court appearance to answer a road-rage charge as unrelated to rugby.

"The England squad are very supportive . . . whether there is any truth in it or not is not the point," said Jonny Wilkinson, the youngest member of the side. "Everyone gets on with him well and has a great deal of respect for him."

At least Dallaglio showed some foresight when he was appointed in October 1997. "I'm not concerned about a higher profile because rugby is now a career and all players have to accept everything that comes with it," he said then. "The important thing for me is that, collectively, England play well and win matches."

The way ahead now looks much bleaker. It will require some remarkable leniency from the RFU to allow him to add to his 26 caps this summer and his chances of touring Australia with the Lions in 2001 must be negligible.

The stakes are high on both sides. By endorsing Woodward's choice of a PR-friendly captain rather than Martin Johnson, the unsmiling Leicester enforcer and successful Lions leader, the RFU knew that it risked a return to the Will Carling era, when the England team's public image eventually became indistinguishable from its captain's.

The difference between Dallaglio and Carling is that Dallaglio's alleged misdeeds could end up shattering the illusions of an awful lot more people.

Several leading players, among them Va'aiga Tuigamala, have predicted that England could win the World Cup. No-one will be so sure this morning.