The Australian Cricketers' Association (ACA) on Friday rejected an improved pay offer from Cricket Australia (CA) and advised players not to sign new terms put on the table by the governing body.
A week before the June 30 deadline for the impasse to be resolved, CA executive general manager Kevin Roberts sent a letter to the ACA with a new offer in a bid to end the stalemate.
CA said recent meetings had been "encouraging", but the ACA responded by describing the new terms as "unacceptable" and stated that an agreement on "many fundamental issues" has still not been reached.
The players' union also warned that the CA letter sent to players does not reflect just how far the parties are away from ending the dispute and called for emergency mediation to be conducted at CEO level.
The letter said CA was offering an increase to the players' share of international cricket surpluses and all domestic players were included in sharing arrangements.
It also said it was offering to increase annual pay rises to male state players.
A statement from ACA president Greg Dyer said: "The current talks between the Australian Cricketers' Association and Cricket Australia have failed to achieve a breakthrough.
"With only seven days until the June 30 deadline, the ACA calls for emergency mediation to be conducted at CEO level.
"With this the ACA continues to search for ways to resolve the dispute. We are motivated by a sense of duty to the game and its players and frustration at the current process.
"The ACA are instructed in this call by Australia's male and female cricketers, who are determined to ensure every avenue is explored to avoid the post-June 30 cliff.
"We are hopeful that the common sense offers of flexibility made in negotiations will be treated more respectfully in an elevated and mediated environment.
"As things stand, from June 30 most of Australia's elite male and female cricket players will be unemployed, jeopardising upcoming tours and ultimately the summer of cricket."