Warning for Man United, Man City and Real Madrid - Daniel Levy will demand huge transfer fee for Harry Kane and dealing with Tottenham chairman was 'painful' for Sir Alex Feguson

The deal makers at Old Trafford - as well as Man City's and Real Madrid's - will be well aware of this when weighing up moves for Harry Kane.

The top scoring striker is believed to be ready to quit his boyhood club in the summer if they fail to qualify for the Champions League this season.

Spurs are in the League Cup final, but are off the pace in terms of finishing among the Premier League's top four.

And former manager Harry Redknapp says anything other than a place among Europe's elite will be deemed a failure.

Redknapp, though, believes only a 'king's ransom' will be enough to prise Kane away from north London.

"Daniel drives the hardest bargain in the world and unless he gets what he wants and a deal that suits Tottenham then [Kane] won't go," he told talkSPORT.

"He's going to demand a king's ransom to give him the money for whoever he wants to buy and rebuild the team.

"Unless he gets that then Harry won't be going anywhere."

Kane has often been linked with a move to Real Madrid as well as league rivals Man City and United.

Old Trafford bosses will be able to attest to how difficult it is to deal with Levy owing to the painful saga involving the purchase of Dimitar Berbatov.

In 2008, United paid £30.75m for the Spurs striker shortly before the transfer window closed, with 20-year-old Fraizer Campbell moving the other way on a season-long loan as part of the deal.

"Dimitar is one of the best and most exciting strikers in world football," manager Sir Alex Ferguson beamed when the deal was done.

"His style and ability will give the team a different dimension and I'm sure he will be a popular player with the fans."

But Levy ensured he eked every last penny from Fergie and the hierarchy, as he detailed in his 2015 book, Leading.

"Daniel Levy, chairman of Tottenham, nailed us to the flagpole in 2008 when he took us all the way to the last day of the transfer window before agreeing terms for Dimitar Berbatov, Tottenham's talented Bulgarian striker in whom we had long had an interest.

"When we got wind of the fact Levy was trying to sell Berbatov to Manchester City, we stuck in our oar, chartered a plane and flew the player to Manchester, agreeing on terms with the player and, as I thought, a transfer fee with the club.

"Then Levy came back to us and said he needed Frazier Campbell, one of our young strikers, as part of the deal. [Chief executive] David Gill demurred, so Levy then upped Berbatov's transfer fee a little.

"Finally, in order to get the deal over the line, and to add insult to injury, we sent Campbell on loan to White Hart Lane and paid the increased fee. We were up until midnight signing and faxing papers to make sure all the paperwork went through before the deadline expired.

"That whole experience was more painful than my hip replacement."

A warning then to the rest of Europe.

If history has taught Manchester United anything, it's that dealing with Tottenham chairman Daniel Levy is a pain in the backside. Or hip.