The completion of the new Wembley Stadium could be further delayed.
Wembley will not be ready until after September
The venue was due to have been completed in August 2005, but hold-ups have led to events, such as this year's FA Cup Final, being rescheduled
Now construction firm Multiplex said the £757m north London stadium will not be finished until after September.
It blames the venue's owners Wembley National Stadium Ltd for not starting work needed before it opens. The company rejected Multiplex's claims.
Once the building work has been finished, stadium owners Wembley National Stadium Ltd (WNSL) has said it will need two months to hold "test events" at the stadium for safety reasons before it can host a major event.
The statement from Multiplex said: "In order to achieve practical completion of Wembley Stadium certain works which are the responsibility of WNSL rather than Multiplex must first be completed.
"WNSL has not begun some of these works."
But WNSL chief executive Michael Cunnah said in a statement: "Wembley Stadium firmly rejects Multiplex's statement and refutes any claims that they make against us.
"The delays experienced on the stadium have and continue to be under the complete control and responsibility of Multiplex.
"The situation remains the same - Multiplex need to make more progress in delivering the stadium before we can name an opening date."
The venue was due to host its first event - the 2006 FA Cup final - in May, but in March the Football Association announced no events would be held at the venue this year due to delays in its construction.
England are expected to play at the new stadium for the first time next year.
Once the building work has been finished, WNSL has said it will need two months to hold "test events" at the stadium for safety reasons before it can host a major event.
In March, bookmaker William Hill was offering odds of 7/2 that Wembley will not be ready for the 2007 FA Cup Final and odds of 1/6 that the stadium would stage the match.