The collaborative move has been made by the Association of Directors of Children's Services and the Children and Family Court Advisory and Support Service (Cafcass) amid rising care applications and continuing delays in care proceedings.
A 26-week time limit on care proceedings was introduced in 2014 but most recent Ministry of Justice (MoJ) figures, which cover the period July to September 2016, show that 37 per cent cases are still not completed within the timescale.
The MoJ figures also show a 21 per cent hike in the number of public law cases heard in the family courts between July to September 2016 and the same quarter in 2015.
The focus of the ADCS and Cafcass joint agreement is a commitment for social workers and court guardians to work more collaboratively to speed up cases and, where possible, divert them away from court.
This involves working together on presenting evidence, drawing up care plans and resolving disagreements before they go to court. Cafcass has also made a pledge to share its national and local data with councils.
"Avoidable delay for a child must be just that - avoided," the agreement states.
"We support a culture of urgency about reaching decisions and want to reinforce the importance of local authorities and Cafcass working effectively to make sure that each child who becomes the subject of care proceedings achieves the level and type of permanence they need as soon as possible."
The agreement goes on to set out that guardians' independence needs to be recognised and that not all issues will be resolved before they reach court. But it adds that "it is in the interests of the child for the guardian to fully engage with the social worker to seek to reach a consensus".
ADCS family justice lead Andrew Webb said: "This agreement confirms the expertise of social workers in the courts and the vital role they play in securing swift, safe outcomes for children at risk of harm.
"The commitments made by both ADCS and Cafcass will help not only on a day-to-day basis, but on supporting the system which is under continuing demand and financial pressure and shows no signs of easing."
Cafcass chief executive Anthony Douglas said: "This agreement reaffirms the positive working practices already in place across most local authorities and Cafcass."
He added that the commitment to share Cafcass data with councils will "help with planning and managing resources".
