Real Madrid could have to pay up to €15million (£12.96m; $17.45m) to secure Jose Mourinho’s appointment as manager following the expiration of a break clause in the 63-year-old’s contract at Benfica.Mourinho is close to returning to Madrid for a surprise second spell after the Portuguese manager signed a three-year deal to replace Alvaro Arbeloa.As The Athletic has previously reported, Mourinho’s deal with Benfica included a release clause of around €6million (£5.2m; $7m). This was valid for 10 working days following the end of their season — and expired on Friday (May 29).Why didn’t Madrid activate the clause if they had already closed an agreement with Mourinho? The answer lies in Florentino Perez’s decision to call a presidential election.Madrid’s pursuit of Mourinho, who was their coach from 2010-2013, has been led by Perez. The Athletic first reported on April 28 that he was the 79-year-old’s favoured candidate for the role of manager next season, and discussions progressed as Madrid ended a second consecutive campaign without a trophy.Perez then held a rare and remarkable press conference on May 12. He took aim at perceived enemies “in the shadows”, saying there was a campaign to remove him from the position he has held unopposed since 2009 and announced an election — despite having an active mandate until 2029.Perez announced presidential elections in May (Javier Soriano / AFP via Getty Images)Enrique Riquelme, a 37-year-old renewable energy entrepreneur, is now standing against Perez in a vote that will be held on June 7, with around 100,000 Madrid club members eligible to cast their ballot.Perez is still able to perform his job as president while the election campaign is going on — Antonio Rudiger’s contract was renewed last week and work has already begun on the make-up of Mourinho’s backroom staff and summer recruitment.Indeed, Madrid reached an agreement with Mourinho in the week following Benfica’s final match of the season on May 16. That is when the manager signed a three-year deal.However, those conversations took place at a time when it was not absolutely clear that Madrid would be holding a presidential election — as Riquelme did not announce he was running until May 23, one day before the expiration of a two-week deadline to do so which began with Perez’s announcement on May 12. If no rival candidate had come forward, Perez would have been declared the winner (as has happened on five previous occasions since 2009).Initially, the formal announcement and unveiling of Mourinho as Madrid’s next manager was planned to take place during the week starting Monday, May 25 — two days after their final game of the season. The election meant this was delayed.Perez is the favourite to win another term at Madrid, but clearly a decision was made not to meet Mourinho’s break clause with Benfica. If it had been, the Portuguese club — who have been actively pursuing potential replacements, including Fulham’s Marco Silva and ex-Manchester United boss Ruben Amorim, who is not keen on the job — would have been obliged to publicly communicate this to shareholders.Sources familiar with the situation, speaking anonymously to protect their position, say Mourinho’s clause at Benfica now stands at €15million.Madrid and Benfica could reach an agreement separate to that figure, but two further sources familiar with the case say they do not believe the Portuguese club are likely to negotiate. A Madrid source repeated the club’s commitment to bringing Mourinho in.It is unclear whether Perez plans to announce Mourinho’s expected arrival as part of his presidential campaign, a strategy that might help him win votes. Riquelme has insisted several times he will soon give the names of a sporting director, a new manager and two star players he says he has reached agreements with.Madrid’s discussions with Mourinho and his representatives included plans for him to bring several members of his trusted coaching staff to the Bernabeu, as well as the need to strengthen various positions, with a particular focus on defence.Mourinho is expected to join Madrid along with his Benfica assistants Joao Tralhao and Pedro Machado, analyst Roberto Merella, fitness coach Antonio Dias, and goalkeeper coach Nuno Santos.Despite the arrival of Dias and Santos, Mourinho is open to keeping Madrid’s physical trainer Antonio Pintus and goalkeeping coach Luis Llopis, two figures who are highly regarded at the club, by Perez especially. Both are expected to stay.Mourinho’s first spell at Madrid ended in 2013 (Bulent Kilic / AFP via Getty Images)“Mourinho will join to add to the team and make the most of the resources, not to clean house,” a source familiar with the matter told The Athletic.In terms of recruitment, Mourinho has asked for a backup right-back, a left-back to compete with Alvaro Carreras, a dominant centre-back and a creative midfielder.Mourinho and Madrid are also expected to discuss the creation of a new position at the club. The role would see a new member of staff take up responsibilities between the first team and the board, ideally a figure with links to Madrid and or Spanish football, to help with the day-to-day.Perez, however, has avoided clarifying the situation in public appearances in recent weeks.When asked about Mourinho at his May 12 press conference, he replied: “I didn’t think anyone would ask me about him. We’re not at that stage now. Today we’re not talking about football or the manager. Right now there’s a priority issue that I want to resolve. I’m not going to talk about coaches or players.”In an interview with La Sexta the following day, he added: “Do I like Mourinho? I like all the coaches; he has been with us, he raised our competitiveness and from there we won six Champions League in ten years.”Speaking with Spanish public broadcaster RTVE on Thursday, he said Mourinho was “a good coach” but continued: “I’m not going to announce it because I haven’t spoken to him yet.”Riquelme, meanwhile, has made it clear that Mourinho will not be his coach if he wins the election. In an interview with The Athletic last week, he said the manager he would appoint had not previously worked at Real Madrid.Last year, reports in the Spanish media said Madrid paid €8million to bring Xabi Alonso to the Bernabeu when meeting the release clause in his contract at Bayer Leverkusen. Alonso was fired in January and is owed compensation until the end of the season, having since been appointed by Chelsea for next term.Arbeloa may well be owed compensation too. He was promoted as manager from Real Madrid’s reserve team to replace Alonso.