By North-west correspondent Alex Stevens

Manchester United and Manchester City will go head to head this summer over a staggering £150million move for Neymar, Football Insider sources understand.

The bitter rivals and Premier League powerhouses are ready to smash the world transfer record to sign the Brazilian superstar.

The 23-year-old is currently negotiating a new contract at Barcelona but his father Neymar Santos Snr recently cast doubt over his future at the club due to tax issues.

Neymar Sr, whose son is being probed by a Spanish court for alleged corruption and fraud, told a judge that an unnamed club has offered £144million for his son, and the club was not Real Madrid.

As revealed by Football Insider last 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.

Neymar’s father also confirmed in October that United made a world-record offer for the Brazil international forward last summer, which Barcelona flatly rejected.

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

The attacker, who is rated in the £100million-plus bracket, 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.

These seemingly outrageous sums will not put off United and City as they target the most likely member of the brilliant three-man forward line at Barcelona to leave in the summer.

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.

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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.

However, Neymar Santos Sr said in November that a deal was not imminent due to other significant issues.

He said: “We’ve begun contract renewal talks, but there are outstanding issues that concern us, and which need to be resolved.

“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.”