Having wrecked infrastructure, gutted buildings and inundated fields, the October 29 disaster has sparked outrage at the authorities for their perceived mismanagement, with a minister acknowledging that many of the deaths were "avoidable".

Given Sanchez's attendance at the G20 meeting in Brazil this week, that appearance could take place on November 27, the Moncloa Palace added.

Political tensions over the handling of Spain's worst such disaster in a generation have boiled over, with the centre-left central government trading blame with the right-wing adminstration in Valencia, the worst-hit region.

The Valencian regional authorities have been heavily criticised for being slow to react to the weather warning, taking too long to ask people to stay indoors and too slow to provide help.

Meanwhile the opposition has criticised the Spanish government for not taking responsibility for managing the emergency, accusing it of being slow to provide resources for the rescue operation for political reasons.

The socialist government rejects the charge, placing the responsibility for flood management in the hands of the local authorities.

Valencia's right-wing regional governor Carlos Mazon on Friday admitted to "mistakes" in the handling of the floods, while transport minister Oscar Puente on Sunday said that a "significant number of the deaths were avoidable".

"The lives could have been saved with a little more precaution, anticipation and prudence," he told the newspaper La Vanguardia, without giving further details.