LaLiga plans to take Paris Saint-Germain to court over Kylian Mbappe's contract extension, with Javier Tebas insisting he will not "allow a European club to destroy the ecosystem of European football".

World Cup winner Mbappe was widely expected to join Real Madrid when his PSG contract expired in June but instead opted to sign a new three-year deal in the French capital.

That left Madrid and LaLiga infuriated, with Tebas claiming the agreement between PSG and the France international was "an insult to football".

Vincent Labrune, president of France's Professional Football League (LFP), responded by questioning LaLiga chief Tebas' "latest attacks against Ligue 1 and one of our clubs", calling his counterpart's behaviour "completely inappropriate".

France's National Union of Professional Footballers (UNFP) echoed Labrune's sentiments, suggesting Tebas' "offensive, hateful remarks, without restraint or foundation, bring shame and discredit to him".

But Tebas has once again hit back by promising to denounce PSG in an investigation as he questioned how the Ligue 1 champions can circumvent financial fair play guidelines.

"The complaint that we are going to file with UEFA has already been drafted and is being examined," Tebas said at a news conference on Tuesday. 

"But we are not going to stop there, we are going to go to France, we have already hired French lawyers and we are going to denounce the position of PSG before the economic control body.

"We are going to denounce this situation before the courts administrative there. We are not going to allow a European club to destroy the ecosystem of European football."

Tebas also claimed PSG had "lost €300-400million over the last three seasons", referencing reports from French newspaper L'Equipe as he continued his scathing summary of the Parisians.

"This year – it's L'Equipe who says it, not me – PSG will go up to €600m in payroll, they will end the season with a loss of €300m and with higher commercial incomes than Manchester United, Real Madrid and Barca, something nobody believes," he added.

"With these losses and a payroll of €600m, more than Madrid, than Barca, renewing Mbappe is impossible...if there is no deception in the sponsorship or higher capital contributions to what UEFA has established."

As for Labrune's previous response, Tebas insisted he would not comment before then going on to question Qatar Sports Investments' (QSI) ownership of PSG again.

"The problem is the attitude of the owners of the club, because they have no limits, they don't care about losses," he continued.

"They put in as much money as they want, they cheat you with sponsors linked to the state. That is the problem."