Alan Pardew has resigned as manager of First Division Reading.
The 42-year-old said that he had decided to leave the club because he had been denied the chance to speak to promotion rivals West Ham.
But Reading have responded by rejecting his resignation.
"I wish to announce my resignation from Reading Football Club with immediate effect," said Pardew.
"My main issue has always been the opportunity to speak to West Ham, which has been denied to me."
Pardew is top of the Hammers' list as they search for a replacement for Glenn Roeder, who was sacked in August.
Reading and West Ham meet on Saturday but Pardew has insisted that he will stay away.
"Given the forthcoming fixture, I will be taking time away with my family over the weekend to consider my future outside of Reading Football Club," said Pardew.
Reading assistant manager Kevin Dillon will be in charge of the team for the trip to Upton Park.
Madejski confirmed Reading's stance in a statement, which read: "The manager Alan Pardew has tendered his resignation, which the Reading board has not accepted.
"The team will be managed by Kevin Dillon, assisted by the current management team of Brian McDermott, Nick Hammond and Niall Clark, for the game at West Ham on Saturday."
West Ham, who have Trevor Brooking in temporary charge, have made no secret of their interest in Pardew.
But Brooking, who does not want the full-time post, looks certain to be in control for at least one more game.
Brooking is happy to wait
"Obviously I would like to sort it out as soon as possible but we want to try and get the right person," he said.
"I'm concentrating on Reading which is a tough game and other issues don't really come into it."
Pardew stepped up from Reading reserve team boss in October 1999 and guided the club to the Second Division play-off final in 2001.
They lost to Walsall but won promotion the following season as runners-up to Brighton.
Their rapid improvement under Pardew continued last term, when they reached the Division One play-offs, only to lose to Wolves, who were promoted.
Pardew added: "I would like to take this opportunity to thank the players for all the effort they have given me and I am sure they will have continued success at the club.
"Most of all I would like to thank the fans for their support over the last six years and genuinely wish them all the success they deserve."
Reading chairman Madejski has fought hard to keep his manager, saying he was only obliged to allow Pardew to talk to Premiership clubs.