David Moyes says it would cost over £150million to prise Declan Rice away from West Ham but the England midfielder is not for sale.
Captain Rice has just over two years remaining on his Hammers contract, with the option of a further 12 months.
The 23-year-old has been consistently outstanding for club and country, attracting interest from the likes of Manchester United and his former club Chelsea.
Asked if Rice would command a British record transfer fee of £150m, West Ham boss Moyes said: "If you are interested, well, it will be north of that.
"£100m was cheap last summer. £150m just now would be minimum but he is not for sale. What I do know is that it means there are only certain clubs that could even consider it.”
Moyes wants the Hammers to take a similar approach to the way London rivals Tottenham handled Manchester City's interest in England captain Harry Kane last year.
"I look at what Tottenham did with Harry Kane, albeit in a different way," said the Scot.
"They said, 'No, there is a price and if someone wants to pay the price, then we would probably do it. If they don't, then he's not going anywhere’ and they have kept him.
"There will be times when players have got the power but we have got Declan on the best part of a three-and-a-half-year contract.
"Just like Tottenham, they have got Kane on a contract and they control what happens."