HAVANA, JULY 12 -- The Cuban government reaffirmed today its refusal to negotiate the departure of any of 15 Cubans now seeking asylum in foreign embassies in Havana.

The latest political refugee was identified as 27-year-old textile worker Luis Monteagudo Rodriguez, who entered the Spanish Embassy Wednesday and asked for asylum. Monteagudo told embassy officials that he had served a three-year sentence as a political prisoner in a Havana prison until 1988.

Fourteen other Cubans are being sheltered by the Czechoslovak Embassy here and are attempting to leave the country. Five of the 14 say they are political dissidents.

The Spanish Embassy spokesman said Spain does not recognize the right of asylum in its diplomatic missions, but said the embassy would not force Monteagudo to leave.

According to the Spanish Embassy spokesman, Cuba's Foreign Ministry stressed that it would not negotiate the departure of any refugee taking shelter in an embassy. Seven Cubans entered the Czechoslovak Embassy Monday and seven more Wednesday.

The Cuban authorities have criticized the Czechoslovak Embassy for its handling of the case and said the refugees are intent on creating a false picture of life in Cuba. Today, uniformed police took up positions around the Czechoslovak Embassy and diplomats said police were reinforced at the Polish Embassy.

Czechoslovak Foreign Minister Jiri Dienstbier said today during a visit to Montevideo, Uruguay that his government was ready to help the Cubans taking refuge in the embassy and all those who were persecuted in their own countries.