Services for the brightest children risk being "decimated" following the end of Government funding for gifted and talented (GT) programmes, campaigners have warned.
Regional partnerships that delivered support to the most able children are struggling to survive after their funding was axed in March, they have revealed.
The 10 partnerships provided teachers with training in how to develop particularly bright pupils and also laid on "enrichment" activities for children, including master-classes and links with universities.
A three-year funding deal put in place by the Labour government has not been replaced by the Coalition, prompting fears that bright pupils will not reach their potential.
The cuts to the regional partnerships are part of the scrapping of all Government funding to national GT programmes, which had cost up to #163;20 million a year.
Some of the partnerships have managed to survive on financial reserves for the time being, but their long-term survival is in doubt. A number are considering becoming charities so they can bid for grants.
The decline of partnerships follows the cancellation of other GT programmes, including a national register of the brightest children and a funding stream for universities to bolster their work with schools.
National Association for Gifted Children chief executive Denise Yates said bright pupils may miss out.
"There is a real danger gifted and talented education will only be focused in the classroom, but enrichment activities are equally important," she said. "If we are not careful, they will be decimated.
"If the partnerships don't survive, schools won't have any support whatsoever for gifted and talented education."
In Yorkshire and the Humber, the regional partnership ended, but the 12 schools set up and funded by the partnership as regional centres of excellence are trying to maintain a GT network in the area.
In the North East, all partnership work will finish at the end of July. "Our work was sustainable, but we don't have the staffing capacity to organise it," said Sue Blakemore, a GT adviser for Newcastle City Council and a member of the partnership steering group.
"We brokered activities. Providers who ran them may now go directly to schools."
In the South East, schools have only an online discussion forum and a weekly newsletter, which is run by two "facilitators" whose contracts last for a year.
"It is good schools can still talk to each other, but where it goes after March 2012 I don't know," said schools facilitator Lyn Bull.
Maggie Ellis, GT co-ordinator at Blatchington Mill School in Hove, said the loss of the partnerships would "take away opportunities" from children. "They were a catalyst for getting more people involved, and provided support when schools needed it," she said.
Tim Dracup, who was lead manager for GT education at the former Department for Children, Schools and Families, told The TES that GT support was now "spread across different pieces of policies".
"The onus is on people in the field to make the connections, and draw together these different elements of Government policy," he said.
"There are also excellent schools out there doing great things. But we have to be really careful to ensure there is still a good network of all the stakeholders in the field."
A spokesman for the Department for Education said spending on GT children from disadvantaged backgrounds had increased during 201011, with #163;250 for pupils claiming free schools meals.
TOP OF THE CLASS
From 1997 to 2002, Government funding for GT children was spent on helping deprived children in cities.
It was then decided to concentrate on the top 5 per cent of pupils, and between 2002 and 2007 Warwick University ran the National Academy for Gifted and Talented Youth.
The Government then contracted education charity CfBT to run a national scheme for GT pupils via the internet and through regional partnerships and university hubs.
Funding for this work has now ceased.