By Jason Burt and Jeremy Wilson

Luka Modric is considering handing in a transfer request to force a move away from Tottenham Hotspur when the transfer window opens.

Tottenham Hotspur midfielder Luka Modric close to transfer request but Harry Redknapp will demand £50m

Chelsea, , Real Madrid, Manchester United and Manchester City are all interested in signing the 26-year-old Croatian midfielder.

Modric is hoping to hold talks with Tottenham chairman Daniel Levy to ask for a move again and will cite the club’s failure to qualify for the Champions League for the second season running as his primary reason.

Although contracted to Tottenham until 2016, Modric has refused to agree to the improved deal that the club wanted him to sign after fending off Chelsea’s interest last year.

Chelsea made several bids last summer, culminating in an unsuccessful formal bid of £40 million.

If the player leaves, it is understood that Spurs would prefer him to move away from the Premier League although not even Real Madrid are prepared to offer a fee of £50 million, which is understood to be the amount Levy would find acceptable.

Modric is keen to avoid a rerun of last year’s damaging transfer saga, which upset Spurs’ start to the season and would like his future decided after Euro 2012.

Chelsea owner Roman Abramovich made signing Modric a personal quest last year and is understood to have told the player’s advisers that he would continue with another offer this summer. It remains to be seen whether he still has that resolve as he considers how to reshape the club’s squad, which could involve hijacking City’s attempts to sign Lille’s Eden Hazard.

Neither City nor United want to be involved in a bidding war for Modric, who has declared that he would ­prefer to stay in London if he leaves Spurs. He could hugely increase his wages with a transfer but would insist his main motivation is Champions League football.

With fourth-placed Spurs denied a place in that tournament because Chelsea won it, the north London club’s bargaining position has weakened, especially as another of their prize assets, Gareth Bale, has declared that he would not want to miss out in Europe’s leading competition again.

Barcelona are interested in Bale, who is under contract until 2015, but have made it clear they will not pay too much for him.

Levy is moving quickly to try to improve the Spurs squad, however, and it is understood that he was in Holland last night in an attempt to seal the signing of Ajax centre-back Jan Vertonghen, who was named player of the season in the Dutch Eredivisie.

Arsenal have also been scouting the 25 year-old but it is understood that his desire to join Tottenham has been unaffected by Chelsea taking England’s fourth Champions League place. The Belgium international would cost about £11million.

It is also thought that Spurs manager Harry Redknapp was in Paris last week to meet Marseille striker Loïc Rémy, who the club tried to sign in January.

Talks have progressed positively in recent days with Emmanuel Adebayor, whose loan spell expired at the end of the season. Adebayor’s Manchester City contract is worth £170,000 a week, but it is understood that Tottenham are ready to make a £4 million up-front payment if he agrees to a £100,000-a-week deal to remain at the club until 2016.

Spurs are also expected to offer Benoît Assou-Ekotto a new deal. Levy will resist interest in his star players.