Baron has echoed the concerns of his Australian counterpart John O'Neill
RFU chief executive Francis Baron has warned that England may withdraw their bid to stage the 2015 Rugby World Cup because of "massive financial risks".
Baron believes the International Rugby Board's demands for a guaranteed sum in profits has changed the bid process.
"It puts an absolutely massive financial risk on the bidding union," Baron explained.
"Our predictions make it unlikely England could actually make a profit out of hosting a World Cup in 2015."
Eight different countries have expressed an interest in hosting the 2015 event -Italy, South Africa, Australia, Japan and the four home nations.
Wales and Scotland are keen on a joint home nations bid, but England would prefer to make a solo bid, which the International Rugby Board has indicated it would favour.
At the moment we just can't make the numbers work because of the scale of the financial guarantee required
Australian rugby chief John O'Neill has already criticised the cost of hosting the tournament, believed to be £100m and £120m respectively for the 2015 and 2019 events.
Baron added: "The RFU board would have to consider very carefully whether or not it would be prudent to risk the game's money in bidding in the knowledge that almost certainly we would make a substantial loss.
"I have explained to the IRB that England is the largest rugby-playing country with access to some of the biggest stadia in the world like Twickenham and Wembley.
"But at the moment we just can't make the numbers work because of the scale of the financial guarantee that is required."