The leader of Slough Borough Council resigned at a meeting where councillors were set to vote on whether to remove him from his post.
Labour councillor Rob Anderson stepped down during the extraordinary council meeting on Monday evening.
The move comes after the authority's children's services were rated "inadequate" by Ofsted.
Deputy leader James Swindlehurst and councillors Martin Carter and Parvitar Mann also resigned.
Mr Swindlehurst said he would not serve under a new leader.
Following the resignations, Sohail Munawar was voted in as the new leader.
Opposition Tory members previously called for Mr Anderson's resignation in 2014.
In the council's agenda report it said the authority had "lost confidence" in Mr Anderson.
It said he had failed to protect vulnerable children, which had resulted in three critical Ofsted reports and led to an independent trust taking over its failing children's services department last year.
The authority added Mr Anderson "has not acknowledged his accountability for the sustained failure" and "seems to have been more concerned with the reputation of the management than child protection".
"To highlight his incompetence two of the members responsible for failure of the children's services... are proposed by him to be part of his new cabinet, as per notification received by the Labour Group Leader," it added.
"We therefore believe, under his leadership the children of Slough residents are under a greater risk."
On stepping down and leaving the meeting, Mr Anderson said: "I bid you all adieu."