Much of Spain's public spending is done by the country's 17 regional governments, who run healthcare, education and other services. The president of the Murcia region, Ramón Luis Valcárcel of the conservative People's party, has suggested that one way to save money is to start partial charging for healthcare. He recently said that "it is necessary to consider having citizens meet part of the costs" of healthcare and education because the expenditure "is unsustainable". But there is an obvious catch in what he says: 100% of the cost of these services – all of it, not just "part" – is already paid for by these same citizens, via tax. It doesn't come out of Valcárcel's pocket. Those who suggest co-payment for these public services are really talking about how the bill is shared between citizens, not about who pays it.

In Spain's present system, currently under attack, the state guarantees our constitutional rights to education and healthcare, and finances their cost with everyone's money. To each according to his needs, from each according to his abilities: instead of the person who is sick paying more, it is the person who earns more money, because that way everyone can enjoy these rights, regardless of their income.

The champions of co-payment argue that charging a symbolic sum for these services would lead to a fall in demand because people would not abuse them. This might be the case with healthcare, although I do not really think it would make up for it; few people go to the doctor out of choice, and this symbolic payment – no matter how small – would not mean the same thing to everyone. We would run the risk of sick people dying for the sake of saving a few pence. But who "abuses" education? What kind of co-payment would reduce demand in schools without leading to serious problems of social exclusion? If expenditure on healthcare and education is genuinely "unsustainable", then wouldn't it be better to improve its management and perhaps reconsider its income: taxation. But the solution must not depend on making those who have the least pay higher bills.

• Ignacio Escolar is Spain's leading political blogger. As part of our New Europe season, we will be running the daily comment he publishes on his blog.