The BBC has learned negotiations between the partnership building it and the owners of the access land, the Whitehaven Miners Social Welfare Club, have stalled.
Disagreements over the lease are said to be to blame for the problems.
No-one from The Miners Welfare Club has been available for comment.
The partnership behind the £5.5m development includes Copeland Borough Council and Whitehaven Rugby League Club.
Problems agreeing the fee that would be paid to use the land almost led to the plan collapsing in March.
A deal was later struck, although no details of the amount were released.
The stadium is key to Whitehaven's part in the 2013 Rugby League World Cup.
Two games are due to be played at the new Pow Beck stadium and the Scotland team would be based in the town.
However, there are fears if an agreement between both sides is not reached quickly then the stadium would not be built in time, leading to Whitehaven missing out on the tournament and the resultant boost to its local economy.
No-one was available at the Whitehaven Miners Social Welfare for comment but in the past the club has said it does not want the stadium delayed.
Copeland Council confirmed negotiations were still ongoing but would make no further comment.
The future of Whitehaven's new rugby league stadium and its role in the 2013 Rugby World Cup could be at risk again.