Real said United did not submit paperwork in time for Spanish deadline

De Gea will only receive fee if he now plays out last season at Red Devils

A €5m (£3.6m) sum, rather than the suggested €15m (£11m), seems likely

Penalty clause was added to the agreement when two parties agreed terms

His pre-agreed contract with Madrid is believed to have included a clause

Real Madrid's failure to sign David de Gea in this summer's transfer window will not mean he goes to the club for free at the end of the season.

The player's pre-agreed contract with the Spanish club is understood to have included a clause that now obliges Madrid to compensate him for not making the signing this summer.

When the two parties agreed personal terms earlier this summer a penalty clause was added to the agreement. Real Madrid could contest the penalty clause saying they did everything in their power to sign the player but the water-tight contract is unlikely to allow much room for manoeuvre on Madrid's part.

Real Madrid will have to pay a compensation fee to David de Gea if he signs for the club on a free transfer

After seeing his dream move to Madrid collapse, De Gea has now travelled to join up with the Spain squad

The player's pre-agreed contract with the Spanish club is understood to have included a penalty clause

It has been suggested the sum is as high as €15million (£11m) but a €5m (£3.66m) sum seems more likely

Such an agreement is legal in private Spanish labour contracts and it will be built into the player's signing-on fee when he eventually signs.

It has been suggested the sum is as high as €15million (£11m) but a €5m (£3.66m) sum, equal to the amount De Gea would have earned net in his first season at Real Madrid, seems more likely.

The player will only receive the money if he now plays out his last season at Old Trafford without renewing, meaning he can leave without a transfer fee next year.

The Red Devils are at war with Madrid after the collapse of De Gea’s move from Old Trafford to the Bernabeu descended into tit-for-tat accusations and bitter recriminations between the two clubs.

The £29m deal that also involved Madrid goalkeeper Keylor Navas joining United fell through when the Spanish giants failed to register De Gea as their player in time for the Spanish transfer deadline at midnight on Monday.

The goalkeeper (pictured arriving for Spain international duty) saw his dream move to Madrid fail to go through

De Gea was due to leave Manchester United in a £29m move but the transfer failed due to late paperwork

The 24-year-old will now train with his Spain team-mates knowing he remains a Manchester United player

De Gea's switch to Madrid would have seen Keylor Navas (right) join Manchester United in part-exchange

Madrid have been widely blamed for the fiasco with one Old Trafford source describing it as ‘a car crash waiting to happen’.

On an extraordinary day of claim and counter claim on Tuesday, the Spaniards responded by issuing a 10-point statement alleging that United instigated negotiations to end the long-running transfer saga and were at fault for holding up the deal.

It concluded: ‘In short, Real has done everything necessary, and at all times, for these two transfers to go through.’

But United hit back on Tuesday night with an official statement of their own, insisting that Madrid made the first move with an opening offer believed to be in the region of £11m plus Navas, and are to blame for registering De Gea too late.

The club said: ‘Manchester United acts appropriately and efficiently in its transfer dealings.’

MANCHESTER UNITED STATEMENT IN FULL Manchester United notes Real Madrid’s statement on the attempt to sign David De Gea and sell Navas to Manchester United. The Club feels compelled to provide some clarification with the following facts. Manchester United did not seek contact from Real Madrid for the sale of David. David is a key member of our squad and the club’s preference was not to sell. No offer was received for David until yesterday. At lunchtime yesterday, Real Madrid made its first offer to buy David. A deal was agreed between the clubs, which included Navas being transferred to Old Trafford. The deals were dependent on each other. In the last several hours of the process, with Navas at the Real Madrid training ground, Real Madrid were controlling the documentation processes of David, Navas and Real Madrid. Manchester United was in control only of the documentation of Manchester United.• Manchester United sent transfer documents for both players to Real Madrid at 2042 BST. David’s documentation was returned by Real Madrid to Manchester United without the signatory page at 2232 BST. At 22:40 BST, minutes before the deadline, major changes to the documentation came through to Manchester United which immediately put the deals at risk. • Only at 2255 BST were the documents that are needed to cancel David’s contract received by Manchester United from Real Madrid. • At this point Navas’ documentation was still not returned by Real Madrid.• At 2258 BST, the transfer agreement was sent back by Manchester United, uploaded onto TMS and accepted – all before the deadline. • It is our understanding that the deals couldn’t happen because: - Real Madrid didn’t upload David’s documents onto TMS in time (Manchester United did) - Real Madrid didn’t upload David’s documents to the Spanish league in time, per reports it seems some 28 minutes after the deadline. The fact that Manchester United filed the papers on time was acknowledged by the Football Association, who offered to support that claim in any discussions with FIFA. The Club offered this assistance, as well as its own timestamped documents to Real Madrid but they have chosen not to go down this route. Manchester United acts appropriately and efficiently in its transfer dealings. The Club is delighted that its fan-favourite double Player of the Year, David de Gea, remains a Manchester United player. Advertisement

REAL MADRID STATEMENT IN FULL Following Monday's events in relation to the intended signing of the player David de Gea, Real Madrid wishes to state: 1. Manchester United did not agree to open any negotiations over the federative rights of David de Gea until yesterday morning. 2. Real Madrid, despite the difficulties entailed in carrying out a deal of these characteristics on the final day of registration, agreed to initiate these talks. 3. When Manchester United agreed to negotiate yesterday morning, they made it subject to reaching an agreement with Real Madrid's Keylor Navas for the player to join the British club from this season, and stated that it was in contact with the aforementioned player's representatives. 4. Real Madrid and Manchester United quickly reached an agreement for the transfers of both players. Following the drawing up of the relevant contractual documentation required, and with the purpose of proceeding with enough time to process both FIFA's Transfer Matching System (TMS) and the registration with the Liga de Fútbol Profesional, Real Madrid sent Manchester United the contracts at 13.39 Spanish time. 5. Manchester United sent their remarks regarding the aforementioned contracts eight hours later, at 21.43 Spanish time, including minor modifications. As these modifications were not significant, they were all accepted immediately by Real Madrid, with the intention being able to register the player on time both via TMS and with the Liga de Fútbol Profesional. 6. Real Madrid, having obtained the signatures of the players De Gea and Keylor Navas, sent the British club the aforementioned signed contracts at 23:32 Spanish time, before waiting to receive the final documents signed by Manchester United. 7. Manchester United reached a final agreement with the representatives of Keylor Navas at 23:53 Spanish time, and it is at this point that the contracts were sent to the player to be signed. 8. Manchester United entered the details of the David de Gea deal, not those of Keylor Navas, at 00:00 Spanish time, simultaneously sending Real Madrid the signed transfer contracts. Real Madrid received this complete documentation at 00:02 and attempted to access TMS, but it was now closed. 9. At 00:26 Spanish time, FIFA's TMS invited Real Madrid to fill out the details of the player David de Gea, as the period of registration in England remains open until today. Real Madrid, in view of the possible eventuality of an administrative dispute over the player's transfer, decided to send the contracts to the Liga de Fútbol Profesional, despite the knowledge that the deadline had passed. 10. In short, Real Madrid did everything necessary at all times to complete both transfers. Advertisement

Meanwhile, De Gea has had to come to terms with the fact that his dream move may have to wait until next summer when he will be a free agent, and must now return to United to repair his relationship with manager Louis van Gaal and goalkeeping coach Frans Hoek.

But De Gea is confident that he will be welcomed back into the first-team fold and United believe there will be no problem re-integrating him into the squad despite the disappointment of the last 48 hours.

De Gea (centre, pictured alongside Anders Lindegaard) has had to sit in the Old Trafford stands this season