There are fears that the government's Healthy Pupils Capital Programme is being 'abandoned'.

Headteachers are urging the government to reveal how and when schools will be able to access a promised £100 million of funding aimed at boosting pupils' physical and mental health.

The Department for Education launched the £415 million healthy pupils capital programme in February this year, but later revealed that £300 million of this amount would instead be rediverted into the main schools budget.

However, questions now loom over the remaining £100 million, fuelling fears that the programme is being "abandoned".

When the fund was launched, the DfE said local authorities and larger multi-academy trusts would receive an allocation for their schools, while smaller MATs, individual academies and sixth-form centres would be able to bid for grants for specific one-off projects.

The DfE said at the time: "Information on the allocation formula, spending guidance and bidding criteria will follow in the summer."

But Tes has established that these details are yet to be published, and the DfE has been unable to provide any guidance on when the bidding criteria will be announced.

Paul Whiteman, general secretary of the NAHT headteachers' union, told Tes that his organisation had "welcomed the introduction of this funding to support schools and colleges to improve physical education, after-school activities and healthy eating".

He added: "We are disappointed, therefore, that six months on, there is still no clarity regarding how schools can access this funding. This should be announced by the DfE at the earliest opportunity."

The money is set to come from the sugar tax being imposed on fizzy drinks manufacturers in 2018-19.

When education secretary Justine Greening announced the one-off programme earlier this year, she said: "We're investing £415 million in facilities to support sports, after-school activities and promoting healthy eating, so we can secure the future health of our young people."

The subsequent cut in the funding being made available, and the lack of detail around the remaining amount, is also causing concern to sports experts.

Emma Boggis, chief executive of the Sport and Recreation Alliance, said: "We were very disappointed that the DfE reallocated money earmarked for important capital investment to support healthy living, including through the provision of PE and sport facilities, to the core schools budget."

She said: "With less than 25 per cent of the original funding on offer it is even more important for the government to clarify as quickly as possible what funding is now available, the criteria for its use and most importantly how schools can access it, so they can use it to support the provision of PE and sport."

Andy Reed, Director of Sports Think Tank said:

"We want ministers to tell us what is happening as soon as possible otherwise we can only assume this programme is being abandoned."

In a statement, a Department for Education spokesperson said: "£100m from the Soft Drinks Industry Levy will be used for the healthy pupils capital fund in 2018-19.

"This funding will be allocated to schools across the country later this year as part of the government's commitment to improving children's physical and mental health. This will include increasing and improving access to facilities, such as kitchens, changing rooms and sports halls."

The DfE has previously told Tes, in response to claims that it was "hijacking" the sugar tax fund, that it still planned to put all the money raised by the levy towards improving children's health.

It said it planned to spend the £775million of sugar tax money as follows:

• £415m: Doubling the primary sport premium
• £100m: Capital spending to support child health
• £60m: Not been formally allocated but will be spent on other "relevant projects", for example, breakfast clubs
• £200m: For the devolved administrations