The Danish Professional Football Players' Association, Spillerforeningen, are in dispute with the league, Divisionsforeningen, over a new collective bargaining agreement (CBA).
In March, the league announced that the current CBA was to be terminated - a decision that surprised the players' association.
A new agreement remains yet to be finalised, with Spillerforeningen claiming that the new proposals put forward by the league are unsatisfactory.
"The biggest problem is that the club association is rushing the process," said Mads Oland, director of the players' association.
"First, they terminate the CBA without notice and just before the deadline. Second, they have sent us a proposal which will seriously diminish the existing CBA.
"Third, they are trying to lockout the players with the shortest possible time limit. What we need is time to get to an agreement - not to rush things through."
A lockout could threaten the start of the Danish top-flight season on July 20, although some clubs will be in UEFA Europa League qualifying action before then.
