There have been big demonstrations in Spain against the proposals.

The debate promises to be lively but much to the frustration of opposition parties, the Spanish government's absolute majority in parliament means the National Water Plan is likely to go through, although there may be some amendments.

The Socialist Party has put forward an alternative water plan relying mainly on desalination plants, which it says are far cheaper than the $16m plan on the table.

Convergencia I Unio, which holds power in the regional parliament of Catalonia, has asked for a reduction in the amount of water taken from the Ebro, even though it stands to benefit from a new pipeline.

Water protests

During the consultation period, which ended on Monday, the government made it clear that while it was ready to listen to other suggestions, alternative sources must be found for the precise amount of water it says is needed on the parched Mediterranean coast.

Prime Minister Jose Maria Aznar plan aims to tackle Spain's water needs

The National Water Plan proposes sending 1000 cubic hectometres of water through pipelines and canals from the Ebro river basin in north-eastern Spain to the coastal regions of Catalonia, Valencia, Murcia, and Almeria.

The amount is roughly equivalent to a 1bn litres, or 70 litres per person, per day, for a year.

Criticised for being over ambitious, expensive and potentially damaging to the environment, the plan has led to big demonstrations, especially in the region of Aragon, where most of the water would come from.

Aragonese say it will only increase economic disparity between poor regions and those along the sunny Mediterranean which need more water only to increase their profits in tourism or agriculture.

But the government says it is trying to meet current water needs, not accounting for growth.