Fixtures in Spain’s top two divisions face being postponed after the players’ union said it would hold a strike.
Players want a guaranteed wage fund where they would be paid even if their clubs become insolvent, and games over the first two weekends are in jeopardy.
“We are unanimous in our decision,” said players’ union president Luis Rubiales. “The league will not start until a new agreement has been signed.”
The top division, La Liga, is set to start on the weekend of 20-21 August. Second-tier club Hercules have struggled to pay some of their players recently, while Real Zaragoza applied for administration in the summer.
Flanked by Real Madrid keeper Iker Casillas, midfielder Xabi Alonso, Barcelona captain Carles Puyol and other internationals, Association of Spanish Footballers chief Rubiales added: “We are behind all of Europe in this matter.
“Players from the first and second divisions have made the decision to call a strike for the first two matchdays of the season. The players have met with us and decided that enough is enough.”
Last season a proposed strike was called off after players protested about the distribution of television money.
Champions Barcelona, guided by superstar Lionel Messi, begin their defence of the title away at Malaga on Sunday 21 August, while Real Madrid host Athletic Bilbao.
Villarreal, who face Pep Guardiola’s Barca side in the second round of matches, also have to contend with a Champions League qualifier against Danish side Odense either side of the opening weekend.