Wembley chiefs have refused to guarantee that Foster and Partners and HOK Sport's new national stadium will be completed in time to host next season's FA Cup final.
Numerous delays forced the Football Association to stage this year's showpiece
at Cardiff's Millennium Stadium after contractor Multiplex failed to complete the stadium in time for the scheduled grand opening on 13 May.
And with no revised completion date in sight, Wembley National Stadium Limited chairman Michael Cunnah insists deadlines are now low on the list of priorities.
He told BBC Radio Five Live: 'For us the most important thing is not to hit a particular date. The important thing for us is that the stadium is built to the right quality and for the price that we can afford.'
Multiplex said today that the timing of the opening of the troubled stadium was a 'matter for its client'.
In an update to the Australian stock exchange, the company said: 'There are a number of critical works and activities that are the responsibility of our client, and the timing of the completion of these works is under the control of our client.
'The date for the opening of the stadium and the hosting of the first event will ultimately be a matter for our client.'
The firm - which has lost nearly £200 million on the project - is now targeting 13 July for substantial completion, with commissioning finished in September.
Multiplex is also drawing up battle lines with the client, Wembley National Stadium Ltd, over the completion of the scheme.
It added: 'Multiplex has formally advised its client, WNSL, that Multiplex is entitled to substantial and legitimate extensions of time under the terms of its construction contract which will extend the contract completion date until at least September 2006.'
The laying of the Wembley turf will be completed this month.