The International Rugby Board have expressed doubts over suggestions that Wales's Millennium Stadium could host games when the Rugby World Cup comes to England in 2015.
Welsh Rugby Union chief executive Roger Lewis has been pushing for the Millennium Stadium in Cardiff to host pool games involving Wales and up to two quarter-finals not involving the Welsh team.
However, the International Rugby Board is worried that if Wales and England happen to be placed in the same pool then their rivals would lose home advantage twice.
"[There is] no guarantee [for Wales]," said IRB chairman Bernard Lapasset.
"We have two objectives. The first is maximising revenues to be successful, and the second objective is to run a quality tournament for everyone like we have done in New Zealand.
"We opened 12 venues to make it possible for as many fans to participate. It will be the same in England, but which cities in England we have not decided."
Proposed venues to host World Cup games include Twickenham and Wembley in London, Leicester's Welford Road, Gloucester's Kingsholm, Leeds' Elland Road, Old Trafford in Manchester, Anfield in Liverpool and the Emirates Stadium in London.
