An ambitious pledge to stem childhood obesity has been written into the final draft of the Department of Health's next five-year plan, due for publication next month.

According to papers leaked to Health Service Journal, officials at the department and at the Treasury want to set a clear target. The aim, by 2010, is to have halted the increase in obesity among children under the age of 11.

The goal is a huge public health challenge. The government estimates that the number of overweight children has increased by 25% since 1995, with almost 17% of UK children now classified as obese.

But a health department source said ministers had not yet taken key decisions about how the trend could be reversed and could not be assumed to be in favour of a proposed ban on the advertising of junk food to children.

The papers were prepared last week by senior officials at the department and the Treasury for discussion by ministers over the next few days. The papers propose action on child obesity as one of eight targets that health ministers should meet in return for extra funding in the comprehensive spending review. Other targets include swapping the goal of reducing adult smoking rates to 24% by 2010 with a more ambitious objective of 21%.

There would also be a more ambitious move towards cutting NHS hospital waiting times, with the total time from a GP referral to a completed operation being limited to four and a half months. Plans for GPs to improve treatment of older people with chronic ailments would be reinforced by a target to reduce emergency inpatient stays by 10%.

These targets would form the building bricks for Labour's election manifesto.

The Department of Health said none of the policy proposals had yet been signed off by ministers. John Reid, the health secretary, has said he will not take key decisions on the public health white paper before a public consultation in the summer. But the targets being set as part of the Treasury's spending review appear to close off some of his options.