Your research into the constitutional limits of the sources of regulatory production in tax matters has formed the basis for taking a matter of unconstitutionality in Royal decree law 3/2016 to court. This measure was introduced by the Ministry of Finance in 2016 and led to a significant increase in corporate taxation. To what extent is it necessary to tax the activities of the Executive in this field?  

In theory, tax rules would have to respond to principles of tax law, as set forth in the Constitution, but in practice they always obey an undisguised tax collection drive, since they are implemented to raise taxes. That is why, regardless of the political parties in each government, there is a need to monitor the constitutionality of the rules in this area.

How are these rules approved?

Tax rules must be approved by Parliament through ordinary laws. This is a principle that comes from the Magna Carta, from the period of the French Revolution, which consists of affirming that taxes are accepted by citizens through the representatives they choose.

And in this context, the mechanism of the decree law appears. What does it involve?

This is a perversion of the system, since it imposes a very exceptional and flawed form of regulation, through the Executive, without the necessary parliamentary debate, and without following the ordinary legislative procedure. Moreover, as an urgent mechanism, it cannot access as important an area as Company Tax, which I analysed in my research.

How is it that in Spain the decree law is used so routinely?

It certainly has to do with the precariousness of parliamentary majorities, through a misconception of the idea of urgency or due to the tax collection drive, or with financial immediacy beyond ordinary legislative procedures.

How can the Executive's performance be monitored?

The administration has internal controls, but the Government, whatever the party, is accustomed to having an immediate political agenda that sometimes entails going beyond authorised legal controls. In any case, if these mechanisms were to function, this abuse of the decree law would not be incurred.

And this is where the tax lawyer comes in, who can take it to the Constitutional Court if it is a constitutional matter?

Exactly. Lawyers must read the laws with a critical eye to propose improvements that ensure the rules conform to European Union regulations and the laws of the Spanish Constitution. 

In that case, how did you approach the research that led to taking up the issue of unconstitutionality?

I proposed that the misuse of the decree law be considered a violation of the fundamental right to political participation, which is enshrined in Article 23 of the EC. Therefore, passing tax rules through decree laws and not ordinary laws would be a violation of the right to political participation in a representative democracy. The principle of tax legality is infringed if a tax is approved through another method other than through representatives with full participation in political debate.

And from here onwards? 

If the Constitutional Court considers that there is a violation of the right to political participation, citizens will have an open path to go to the CC by exercising their right to appeal, which protects fundamental rights such as this.

In fact, if the unconstitutional nature of the rule in question is recognised, it would save companies over 5.000 million euros. As director of the Bosch Aymerich Family Business Chair, how does this affect family businesses?

It could be of decisive importance. This decree law contained several provisions which, through their nature, may affect operating companies that have incurred losses. To the extent that these structures of companies carry losses, the decision could have a very significant impact in terms of family businesses, especially within the framework of family holdings.

However, this process demonstrates that research in the field of law must also be supported.

Law, unlike physics or chemistry, is not an empirical science. It is a dogmatic science, where the truth is known, but one must know how to interpret it. In my case, I understand this from a dogmatic perspective linked to the study of standards, the proposal for solutions to see how they adapt to real problems and to open new interpretations and ways that make positive law increasingly a fairer law.