West Brom have been warned to expect a tough stance from Birmingham should they press ahead with plans to make Chris Hughton their new manager.
Hughton is believed to be the leading contender to replace new England manager Roy Hodgson at the Hawthorns.
He was interviewed for the job 15 months ago before losing out to Hodgson.
But at that time Hughton was a free agent after being sacked by Newcastle two months earlier, and Birmingham are keen to retain his services.
A source close to City said: "Chris is very highly rated at Birmingham and has done a great job since taking over.
"Blues are planning for next season, want Chris to be part of those plans, and any approach would not be welcome."
Birmingham are anxious to avoid a repeat of last summer when manager Alex McLeish resigned and joined Aston Villa.
That resulted in a lengthy compensation battle and, if City do lose Hughton, they will expect to be fully recompensed in a similar manner.
Hughton signed a 12-month rolling contract when succeeding McLeish.
He led Birmingham to the npower Championship play-off semi-final in a season spanning more than 60 games, despite losing most of the squad which won the Carling Cup.