A briefing published by the Adoption Leadership Board, which was set up in early 2014 to oversee the adoption system, reveals in that it is concerned a slump in adoption placement orders in recent years has led to a "substantial contraction" of adopter recruitment by councils and voluntary adoption agencies.
"The latest available data suggests that there are more approved adopters waiting than children," says the briefing.
"However, we should not conclude that this means there are enough adopters on a simple numerical calculation."
As of 30 June 2016, there were 2,890 approved adopters not linked or matched - more than the number of children waiting, although this figure represents a fall from 3,510 at 30 June 2015.
"This fall in adopters waiting is because of a contraction in adopter recruitment by local authorities and voluntary adoption agencies in response to the lower number of placement orders being granted," the briefing states.
The briefing points out that, of a total of 2,000 children awaiting a placement at the end of June 2016, 560 had been waiting for 18 months or more since entering care.
"This strongly suggests that more still needs to be done to ensure the system recruits, approves and supports adopters who can care for children with the needs that are well known and all too familiar - children with complex health needs or disabilities, children from minority ethnic, cultural, religious and language backgrounds, older children and sibling groups - and that they are then matched with those children waiting," the briefing adds.
The briefing points to the number of adopters being approved falling by 49 per cent between the fourth quarter of 2013/14 and the first quarter of 2016/17, from 1,390 to 710, adding that registrations have seen a similar decline.
The board said the key factor in the fall in placement orders is a reaction in the sector to an appeal court ruling made in September 2013 by Sir James Munby in the case of Re B-S, which criticised social workers for not providing enough evidence that alternatives for adoption had been considered.
Munby clarified this a year later to ensure that councils still pursued adoption where it is in the "child's best interest".
The fall in placement orders also coincides with a rise in the use of special guardianship arrangements where friends and family take on caring roles.
But the board is concerned that not enough research and planning is taking place around such arrangements.
"There continue to be concerns about plans and decisions being made with undue haste when there is no evidence of an established relationship between the child and prospective special guardians or clear exploration of the strengths and risks of such a placement in the longer term," the briefing adds.