Joe Dunne has been sacked as head coach of Sky Bet League Two side Cambridge.
The U's have won just five of their 20 league games this season and sit in 21st place in the table, just three points clear of the relegation zone.
Assistant head coach Mark Bonner will take charge of the first team as a search for a successor to Dunne begins.
Cambridge director of football Graham Daniels said: "It is never easy to part company with a head coach – particularly someone who has played a number of significant roles at the club over several years and for whom everyone at Cambridge has great affection and respect.
"Results have however dictated the need for change. We believe we have the talent in this squad to be further up the table. While the team has shown its ability in patches during the season we have struggled to find consistency.
"As a result the board came to the conclusion that the team would benefit from a change of leadership."