By Spain correspondent Miguel de Souza

Chelsea, Manchester United and Manchester City are on alert after the father of Neymar warned his son could leave Barcelona if he continues to have issues with the Spanish tax authorities.

Neymar Snr, who is also his son’s manager, provided encouragement to the Brazil star’s Premier League suitors by revealing that it is not certain he will sign a new Barca contract.

As revealed by Football Insider in early September, the defending Spanish and European champions are in talks with Neymar over extending his current £230,000-a-week deal, which runs until 2018.

“We’ve begun contract renewal talks, but there are outstanding issues that concern us, and which need to be resolved,” Neymar senior said to Spanish radio station Cadena Ser. “Since we arrived to Spain we have been under attack (from the tax office) and it has extended to Brazil.

“For the last two-and-a-half years, we have had to defend ourselves from accusations.

“We will respect Neymar’s contract with Barça but regarding the contract extension, we need a deal that gives us peace of mind for Neymar, my companies and my family.

“We are not thinking of leaving Spain but we have a problem. We’ve never experienced such major tax issues.

“I don’t want to use the word persecution, but if the working environment here is not good, we won’t be able to remain in Spain and will have to leave the country.”

Hot pursuit: Louis van Gaal sanctioned a shock summer United move for Neymar

Hot pursuit: Louis van Gaal sanctioned a shock summer United move for Neymar

Neymar had plenty of suitors, including top Premier League clubs, but chose to join Barcelona in the summer of 2013 from Brazilian side Santos.

The player has both the Spanish and Brazilian tax authorities claiming outstanding payments for the tax years 2011-2013 and he has had assets worth £31.5million frozen in Brazil.

“We shouldn’t be having to put up with this uncertainty regarding our taxes and whether we are going about things in the right way,” Neymar senior said. “It’s not easy for us because we’re getting it from all sides, from both the Brazilian and the Spanish tax systems.

“We’re speaking with all of these parties to try to work out how we should deal with this issue, because what we don’t want is to still be in Spain two, three, four, five or 10 years down the line and to then receive a nasty surprise which would be unjust.

“We own the Neymar brand, which has been running as a business since 2006 from Brazil, and we need the peace of mind that comes from knowing that everything is in order.

“We need to do things properly, and ascertain whether in Spain we’ll be allowed to carry out our work.”

Football Insider revealed in August that Neymar is targeting a contract worth a staggering £500,000-a-week.

Neymar wants a huge pay rise that will take him close to team-mate Lionel Messi, who is the world’s best-paid footballer with a contract worth £530,000-a-week before taxes.

Triple joy: Neymar has flourished in a front three with Suarez and Messi

Triple joy: Neymar has flourished in a front three with Suarez and Messi

Neymar’s current salary is less than half that of Messi. The Brazilian’s contract is set at £6.4million after tax per year, which, given the income tax rate for Spain top earners of 47 per cent, is the equivalent of £230,000-a-week.

The 23-year-old wants an improved deal that will more than double his pay to £500,000-week and will run until 2021. Over six years, the total package he is seeking would be worth an astonishing £156million.

An improved Neymar contract is a priority of Barcelona, who had always planned to offer the forward a new deal in his third year at the club and recognise they will have to offer a massive deal to keep one of their most important players.

The Brazil international has been a huge success since his move from Santos in 2013, scoring 39 goals last season in a Barca front three that, with Messi and Luis Suarez, scored 122 goals. The club won the Treble and Neymar also scored in the Champions League final.

He has continued in the same vein this season, making light of Messi’s absence through injury to lead the La Liga scoring charts with 11 goals.