Jon Brady says the Cobblers players need to understand that things have to improve after the 2-1 defeat at Swindon Town.
"We led in the first half without not being at our best," he said.
"We knew the importance of nor giving away free kicks around our area but we did so, even so I felt we could have done better with that goal and then in the second half we conceded another goal that I felt was avoidable.
"We are making individual errors in games at key times, and that might be because at the moment, we are not strong enough mentally, either as individuals or as a group. You can't win games of football when you give away goals like we did today. That has to change and we need to make that happen quickly.
"We were not at our best today but we still should have gone in 1-0 ahead at half time but there is a weak underbelly to us at the moment and we need to get that sorted.
"We are in a situation where we are fighting for our lives. We need players to support each other, to support each other, to help each other out but we are not strong enough with each other and time is running out for us right now.
"I have faced every single player in the changing room and told them that enough is enough. Things have to improve.
"We have some good players in the changing room but in this current situation it is not always pretty and easy, you have to fight and battle and then you can play on top of that. Yes, we do it at times but not often enough an we are too happy to feel like we have done enough. We have never done enough and every individual player has to be accountable and responsible for their actions.
"As a player you have to look yourself in the mirror and you can't let yourself be rolled over. You have to fight.
"With our goalkeepers, I have faith in Jonathan Mitchell but I thought he could have done better with the goals today. Steve Arnold is not training at the moment, he has had a back problem and we have been looking after him for the last few weeks. He is declaring himself fit for matchdays but being honest with you, I believe in both of our keepers but if we want to make a change, we have that issue to consider. I'll let the dust settle and then I'll pick a team that is ready to fight for their lives on Tuesday."