Twickenham moved yesterday to repair the latest damage to their bid to stage the 2007 World Cup after Australia revealed that they were in talks with England and South Africa to stage an annual Tri-series at Twickenham from 2004.

An admission by the chief executive of the Australian Rugby Union (ARU), John O'Neill, that the three countries had been in regular negotiations this year has alarmed the three Celtic nations, whose votes in the World Cup battle between England and France next month will be crucial.

The Celts depend heavily on the income they receive from playing one-off Tests against one of the three major Southern Hemisphere nations every November, and any notion that England were part of a plan to strip them of those matches would drive them into the arms of the French.

The chief executive of the English Rugby Football Union (RFU), Francis Baron, went on the offensive yesterday to reassure the Celts that England were not looking to marginalise them and make money at their expense.

"Nothing could be further from the truth," he maintained. "All we, along with Australia and South Africa, are looking to do is replace the International Rugby Board's (IRB) current tour schedule, which is a legacy of the amateur days, with something more satisfactory.

"When John O'Neill talked about a series involving England, Australia and South Africa he was talking about only one element of our vision of the future. All the major touring countries, including Wales, Scotland and Ireland, would host series which would be held once a year in both hemispheres.

"Our argument is that series would be more meaningful than one-off Tests and therefore more financially lucrative, which would work to the benefit of all."

The World Cup vote promises to be close and the winner will need to secure 11 of the 21 votes available. The Scots and the Irish, who have two each, were already tilting towards France and could now be further alienated.

Wales were more likely to back England, but are unlikely to do so if they think England are trying to hive off the Southern Hemisphere nations for themselves. The RFU has worked assiduously on Argentina and Canada, who each have one vote, which with its own two would give them 10.

Any change to the tour schedule will have to be agreed by the IRB which would have reservations about the impact the biannual series would have on the World Cup, which is staged every four years, while they could also threaten the commercial viability of both the Six Nations Championship and the Tri-Nations series.

"I do not believe the World Cup would be undermined," said Baron, "while the Six Nations is most certainly not under threat. All we are trying to do is come up with fresh ideas which would work to the benefit of everyone. It is a decision for the board and I would like the major touring nations to all meet together and thrash this out. It is certainly not a case of England trying to go our own way."

The ARU said that in the proposed series the three nations would play each other once each before the top two teams play in a final at the end of a month-long tournament.

South Africa followed Australia yesterday in saying that a proposal for the triangular series would be put to the IRB.

"SA Rugby Ltd supports the concept as it will have several benefits for the three countries and the game in general," it said in a statement.

"We have held exploratory discussions with Australia and England in this regard and it has been agreed that we will jointly submit a full proposal to the IRB for discussion at its council meeting in November.