David Cameron today called for an end to the "tick-box mentality" in adoption services as league tables naming poor performers were unveiled.
The Prime Minister said officials were spending too much time asking prospective parents "pointless questions" and urged them to show more "discretion" and "judgment".
He also warned local authorities that "go on year after year failing" children waiting for adoption that they will lose the right to run the service.
Mr Cameron said: "Time is not just money in these cases. Time can lead to tragedy."
During a visit to a children's centre in north London, he added: "Everyone wants to make sure that adoptive parents are asked the right questions and that we have proper checks and safeguards, but there are far too many stories today about pointless questions, very intrusive questions, and also a sort of tick-box mentality that means that people are looking at things like how long ago you gave up smoking, the age of your youngest natural child.
"There's too much ticking of boxes and not enough discretion, judgment and responsibility."
He continued: "We want to act to help some of those vulnerable children in our country, children who languish in the care system who have a terrible start in life. And often, as a result, go on and have really difficult lives. We want to do more to help those children.
"The state is responsible for them and frankly the current situation isn't working."
Hackney, in London, was named the worst performer over the last three years for placing children up for adoption quickly.
Just 43% of youngsters were found new homes within 12 months, the Department for Education's league tables show. The national average was 74% from 2008-2010.
Other poor performers included Brent, with a 52% rate, Nottinghamshire on 55%, and Derby and the East Riding of Yorkshire, both on 57%.
York came out top, with a 100% record of enabling children to go to new families within one year. It was followed by South Tyneside on 96%, Hartlepool on 95% and Portsmouth and Windsor and Maidenhead on 94%.
From a three-year average covering 2009-2011, just 12% of children in care in England were successfully adopted, according to the figures.
Though Derby was among the slowest to get children adopted, it was the highest for overall adoptions with a rate of 26%, followed by North East Lincolnshire with 25%.
The lowest scoring were Solihull with 3% adopted, Bracknell Forest, Haringey and Kensington & Chelsea with 5%.
Alan Wood, director of children's services at Hackney Council, warned of the future danger of local authorities "playing the league table game".
"I think we will see an increase in the number of adoptions coming forward," he told the BBC.
"I just want to hope and believe that that is because that is the right decision for the child, and people have not been playing the league table game like they used to play with schools and the police and the health service, when league tables were initially introduced there."
Mr Wood also said the information released by the Government was out of date and that over the last year Hackney had achieved a 100% rate for placing children within 12 months.
"It's not data that reflects the current position," he said.
As part of its attempt to shake up adoption services, the Government has also published an "Adopters' Charter", which it claims tackles the "persistent myths" that people who smoke, are single, or are overweight cannot foster or adopt children.
Later this week, the final report by former mandarin David Norgrove into the family justice system, which processes care and adoption orders, will be published.
It is expected to call for restricting the duration of court cases to six months - instead of the average 13 months now.
The Local Government Association (LGA) called on ministers to remove the constraints that stop councils acting more speedily but warned against a "one-size-fits-all" system.
David Simmonds, chairman of the LGA's children and young people board, said: "We acknowledge that there is a variation in performance across councils and recognise that at times the system has been risk-averse, but we want to work with Government to change that and remove barriers that delay decisions, including tackling the significant delays in the family courts.
"A one-size-fits-all approach is not the right solution for some children."