The Football Association insists the new Wembley stadium will be completed in time to host the 2006 FA Cup final.
And, while it is putting contingency plans in place if Wembley is not ready by 13 May, the Millennium stadium says it has yet to be approached.
"We are willing and able to host the 2006 FA Cup Final, if Wembley is not," said Millennium stadium chief executive Paul Sergeant.
"But the facility has not been provisionally booked by the FA."
He added: "The date of next season's final is free in the stadium's busy event calendar, but there is currently no agreement preventing another event from making a booking.
"We are in contact with the FA on a daily basis and would of course let them know if another event organiser wanted to book us for that date.
"There is no question that we would not offer them the first right of refusal should we receive an approach from another source, but until that should happen the question is incidental."
The FA had earlier issued a statement stating its confidence that the England's new national stadium would be completed on schedule despite the project having its doubters.
In a statement on their website, the FA said: "Multiplex are the expert contractors working to a fixed price contract.
"Therefore we have to be guided by their experienced advice that Wembley will be handed over to the FA by the end of March 2006 and be open for the FA Cup Final.
"However, it would be naive of any organisation involved in such a huge building project not to have alternative plans in place - should any unforeseen problems occur.
"Therefore, the FA is currently in negotiation with an additional venue - purely as back up.
"The public would expect that when we are responsible for hosting the most prestigious domestic cup competition in world football.
"We would also like to make it clear that we would only consider a fallback venue which has a proven track record of hosting FA matches."