Port Vale have sacked manager Darrell Clarke ahead of their Tuesday visit to Portman Road.
Vale are 18th in League One, six points off the drop zone having won only two of their last 18 matches.
At the weekend, the were defeated 3-2 at Lincoln City had had two players sent off, taking their tally of red cards to four in three games.
Clarke’s assistant, Andy Crosby, will take charge on an interim basis until the end of the season.
David Flitcroft, Port Vale’s director of football, told his club’s official website: "Firstly, it is important that we place on record our appreciation to Darrell for the role he has played in a successful chapter in the club’s history, culminating in last season’s promotion to League One via the play-offs [last season].
"We have been on an emotional journey together, during which time Carol, her family and all associated with Port Vale have provided unwavering support to Darrell throughout an unimaginably difficult period in his life.
"We have immense gratitude to him for his role in driving the club away from potential relegation from League Two to winning promotion to League One.
"However, following discussions in recent weeks with Darrell, the backroom staff and senior players, we have decided now is the best time to make a change and give ourselves the best chance of retaining the League One status we have all worked so tirelessly to achieve since the Shanahan family purchased the club in 2019.
"We must now work together as a staff and supporters to help Andy Crosby and the players to secure the points required to allow us to build on the foundations we have laid and continue our progression this summer.”
Vale co-owner and chair Carol Shanahan OBE added: "Collectively, this has not been an easy decision to make, and given the close relationship we have developed during the past two years, it is difficult to part ways with Darrell professionally.
"We always wish to give our manager ample opportunity to deliver results, though at this stage we now agree it is in the club’s best immediate and long-term interests to make a change.
"We — staff, players and supporters — must now work together over the next three weeks to do everything we can to positively influence the team on the pitch and retain our League One status.
"We know a detailed review of the last few months is required to understand where mistakes have been made and we will commence this at the conclusion of this season. Now, though, is the time to come together and all play our part in the final four fixtures of the campaign.
"We wish Darrell well in his future career and he and his family will always be welcome here at Vale Park.”