The former Real Madrid general manager Jorge Valdano claimed last week that Spain's big two are reaching a crossroads. Soon, he said, Barcelona and Real Madrid will find themselves in a situation in which they have little choice but to seek out new challenges elsewhere, leaving La Liga behind for a European league.

It is a subject that was in the background when the European Club Association met in Geneva on Tuesday but, as Valdano admitted, while Madrid and Barcelona would welcome such a move, rather more questionable is whether Europe's other big teams will have the same enthusiasm for leaving domestic competition behind.

"With every passing day there is a greater gap between the two greats and the rest of the league in Spain," Valdano said. "You look ahead and the sensation is that this situation will only get worse. There will come a time when this [situation] does not suit the big two either. In the future Madrid and Barcelona will have to look at teams that travel at the same speed as them and that will lead to a European league.

"There are two teams whose market is the whole world and the rest whose market is just their [regional] community. We are in a moment of transformation, which depends on what happens in Spain and in other leagues. The problem is that the Premier League works, Germany works: there is a lot of money there and a lot of passion for [domestic] football. They do not seem especially enthusiastic about leaving their leagues."

The fact that Valdano was asked about the future of La Liga illustrated the extent to which inequality is now definitively, if belatedly, on the agenda in Spain – reflected by an opening weekend which was met with dread as much as delight after Real Madrid defeated Real Zaragoza 6-0 and Barcelona beat Villarreal 5-0. The president of Sevilla, José María Del Nido, described the Spanish league as "rubbish – the greatest pile of junk in Europe".

In answering as he did, Valdano revealed an essential truth. He also revealed a sleight of hand, portraying Spain's big two as innocent victims of a league that simply cannot compete with them, rather than perpetrators of an inequality that threatens to destroy it. He also hinted at the threat that forever hovers in the background: the departure from La Liga of Madrid and Barcelona. It is a threat that, for now at least, suits no one but is used as a weapon on both sides of the divide.

There will come a time when the situation in La Liga does not suit the big two. But if so, Real Madrid have been complicit in that – either blind to the consequences of their actions or all too aware of them and thus deliberately destructive in their approach.

Last season Valencia, in third, finished 21 points behind second-placed Madrid – and that was an improvement on the previous year. Third place was closer to relegation than the title. Over the past two seasons, both Madrid and Barcelona have smashed previous records for points totals. It is not that one of them will win the league so much as the fact that it is hard to see them failing to win many games. A season in which both teams are not beaten once, in which the opposition does not even try, is not so far away.

Underpinning that dominance is the distribution of TV money. Deals are struck individually. Madrid and Barcelona each make €135m (£118m) a year on domestic rights alone. Valencia make €48m, Atlético €46m and Sevilla €31m. Racing Santander make €13m, less than a tenth of the top two.

Madrid and Barcelona have long resisted calls for more equality on the grounds that they generate the vast majority of the money in a country where 60% declare themselves as fans of one of the big two and where the media are divided down the middle, supporting Madrid or Barcelona and largely ignoring the rest. A new proposal is on the table under which a collective deal will be drawn up but the inequality will be enshrined, with Madrid and Barcelona getting 35% of the money to themselves.

One of the reasons that Sevilla and Villarreal have been so outspoken about the new plan is not so much that they see Madrid and Barcelona get further away but that they have been manoeuvred into fifth and sixth place rather than the third and fourth to which they aspired. Other clubs have given in as a way of simply securing survival. There is no sense of collective identity, no "league" to speak off – just a confederation of clubs in which the voice of two is heard louder and more often than anyone else.

What ground Madrid and Barcelona have ceded in terms of the percentage is made up in the prospective total in the new deal (which is yet to be ratified and may still meet resistance). That is a total – and this is the key – that allows Madrid and Barcelona to maintain a huge advantage over the rest of Europe, where their sights are now truly trained. One hundred and thirty-five million euros over the €69m Manchester United get is a huge advantage. It matters little that Valencia, say, can draw closer to you if you can still double their income and at the same time draw further away from teams in Milan and Manchester.

The big two insist that the difference domestically is only fair, reflected in the colossal difference in figures relating to merchandising and marketing. Almost half the Spanish league do not have shirt sponsors this season. Publicly the big two rarely speak out but in private they bring their huge muscle to bear on the rest with a simple, if effective argument: you only fill your grounds and get big TV audiences when you play us. According to El País, Madrid versus Barcelona in the Spanish Super Cup took a 62% audience share in Spain; that same week Villarreal's Champions League qualifier was not among the 20 most watched programmes that day. The dominance in international interest is even greater yet.

So, when Villarreal's president, Fernando Roig, says: "I'd like to see Madrid and Barcelona have a league that consists only of the clásicos – that would be pretty boring," the response from Madrid and Barcelona is: and we'd like to see you try to have a league without us.

When Del Nido described the league as "rubbish", it did not take long for the Madrid defender Sergio Ramos to respond and, in doing so, to say it all. "If Del Nido doesn't like it, he can find himself another league," Ramos said. "We like the league the way it is."