Joint-managers Jim and Danny Ward quit Sittingbourne because they could no longer work for new chairman Maurice Dunk.
The pair took letters of resignation along to Brickies' Kent Senior Cup tie at Chatham on Tuesday night.
They remained open to staying on but failed to get the assurances they were looking for following the 3-0 win and quit on the spot.
Jim revealed the brothers had been considering their future for a fortnight.
He said: "Maurice Dunk moved the goalposts. We were given a guaranteed wagebill for the first three months of the season and that was taken away.
"We were working with one hand tied behind our backs and we couldn't do it any more.
"We knew a budget cut was coming. It's been horrible working under those conditions.
"It's been amateur ever since we left Bourne Park and walked into Woodstock.
"Little things, like he wouldn't let us have keys to the place and we had to stop training at 8pm because we couldn't have the floodlights on.
"It's a lovely club, the fans are excellent and I have so much time for Andy Spice (former chairman).
"He's a lovely man and kept the club going for all those years with his wife Tanya.
"It's a shame it's come to this but I wish the club all the best for the future."
Bourne chairman Mr Dunk has placed coach Matt Wyatt and captain Nick Davis in temporary charge for the home game against Worthing on Saturday.
Mr Dunk said: "I realise I'm going to be the enemy of the supporters over what's happened.
"I'll be seen as the new guy who's forced out the managers.
"But at the end of the day, Jim and Danny resigned so what can I do?"
"The committee saw things differently to them.
"We both want to get to the same place but they want to gallop ahead, whereas I feel we need to stabilise the club and take our time.
"I cannot stress enough that when the club left Bourne Park, there were two options - move to Woodstock or fold.
"I'm prepared to take things slowly to be successful.
"To take the club to the next level, we need more money than we can afford at the moment."
Brickies have lost five of their opening six games in Ryman League Division 1 South but were confident of climbing the table and mounting a play-off challenge.
So the squad were shocked when Ward addressed them after the Chatham game.
He said: "They were gobsmacked. I only ever tell them the truth and that's what I did.
"It's a great squad and if I walked into another job tomorrow, I'd want to take most of them with me.
"We took letters of resignation along to the game.
"I wasn't 100 per cent sure we were going to quit but we needed assurances after the game and we never got them."