The top six-ranked Spaniards, including Maria Jose Martinez Sanchez (25) and Anabel Madinah Garrigues (53), last week accused the national tennis federation (RFET) of failing to provide enough support for the women's game.
The RFET refutes the accusations, saying that it was investing more in women's tennis than ever and was open to dialogue with the players and suggestions for improvements.
Sanchez-Vicario, a four-times grand slam singles champion and former world number one, and 2004 Wimbledon champion Martinez issued a joint statement on Monday with 51 other current and former players backing the six, local media said.
The statement denounced "the general apathy shown by the federation toward women's tennis in recent years."
The Spanish women's game lags behind the men's and there are only four players in the WTA top 100 and none higher than 25.
Men's world number one Rafa Nadal is one of 13 Spaniards in the ATP top 100, with Fernando Verdasco the next highest at eight, David Ferrer at number 11 and Nicolas Almagro in 16th.
An RFET spokesman said the federation had not received any communication from Sanchez-Vicario, Martinez and the other players and it was standing by the position it set out in a statement on its website (www.rfet.es) last week.
