Italy has emerged as a major contender to host the 2015 World Cup with Twickenham still concerned about the £80m fee the International Rugby Board is demanding for the right to stage the event.

Even though the IRB reduced the fee from £100m last week, the Rugby Football Union still calculated that it would lose £5m on the tournament.

Unions have until May to submit a tender to host the 2015 and 2019 World Cups and the Italian Rugby Federation has received a pledge from its government that it would guarantee the IRB's £80m. Russia's governing body has received a similar promise from its government for 2019, but the RFU has been told it only has a chance of central assistance if its bid guarantees matches in Wales, Scotland and Northern Ireland.

The RFU has been considering including Wales in its bid. The only money a host union keeps is ticket receipts and there are concerns that Scotland, especially, would struggle to achieve sell-outs, even in matches involving their national side.

New Zealand is expected to take a £10m hit in 2011. "As a business case, the tournament does not stack up," said the chief executive of the 2011 organising body, Martin Snedden. "While I am confident that it will be a success, I have to make sure that we do not have a financial disaster on our hands. The financial model for the host is pretty repressive. We pay for everything."

The RFU is far from certain to make a bid given the financial implications. That is a concern for the IRB which, given the relatively low return expected from New Zealand, needs a commercially strong tournament in 2015. Italy has the infrastructure to host the event, but rugby is a minor sport in the country and it would be a struggle to sell tickets for many of the group games.