West Ham accused Tottenham of trying to unsettle Scott Parker after forcefully rejecting their bid for the midfielder.
In a strongly-worded statement, West Ham reveal they had sent a hands-off warning to Tottenham chairman Daniel Levy before he tabled a bid for Parker.
Upton Park chairman David Sullivan dismissed Spurs' subsequent offer - reportedly valued at £7million - and insisted Parker was not for sale at any price.
A Hammers statement read: "The club informed Tottenham chairman Daniel Levy prior to him making the offer that we would not welcome any approach to unsettle the player."
Parker has been linked with Spurs and Aston Villa all summer after playing an integral role in West Ham's top-flight survival last season.
The 29-year-old was the shining light in a struggling team and forced his way into England's initial World Cup squad.
Sullivan vowed at the end of last season that Parker would not be sold - and he insisted today that West Ham would not break that promise under any circumstances, for any amount of money.
West Ham have a tradition of selling on their best players. England players Rio Ferdinand, Frank Lampard, Michael Carrick, Joe Cole, Glen Johnson and Jermain Defoe all came through the Upton Park ranks.
But Sullivan sees Parker as the man to lead West Ham into a bright new era and the club have opened negotiations over a new five-year deal.
"I made a promise that I would not sell Scott and I will not, for any amount of money, break that promise to the West Ham supporters," said Sullivan.
"Scott is not for sale at any price, to anyone. West Ham supporters, for far too long, have had owners that sell their best players and promise one thing and do another.
"This is a new era. We are building a bigger, better West Ham and when we make a promise, we honour it."
West Ham have signed midfielder Thomas Hitzlsperger, winger Pablo Barrera and striker Frederic Piquionne and new manager Avram Grant has also been chasing defender Tal Ben Haim and Nice striker Loic Remy.
Carlton Cole and Valon Behrami have also been linked with summer moves away from Upton Park.
Sullivan had admitted that West Ham, who have debts of around £80million, would have to listen to offers for all players other than Parker.
But vice-chairman Karen Brady told BBC London: "What is equally important (as bringing players in) is to not let players go. We have had offers for our players that we have not accepted."
Grant today completed his backroom team with the appointment of former Yugoslavia international Zeljko Petrovic as the club's new assistant manager.
Grant had identified the appointment of Petrovic, 44, when he took over at Upton Park earlier this summer.
Petrovic completes Grant's senior backroom staff and he will work alongside senior coach Paul Groves, first team coach Kevin Keen, goalkeeping coach David Coles and fitness expert Eamon Swift.Reuse content