Police Federation's fears over cuts to online safety work
Work to stop children falling victim to abuse and bullying could be hampered by police cuts, the Police Federation chairman has said.
Paul McKeever said cuts to forces could move resources from work in schools on online safety to front line services.
Online child safety watchdog CEOP also said its budget was being cut despite the risk of online abuse growing.
The Home Office said CEOP had agreed it was able to maintain its staffing levels under the current budget.
CEOP's warning comes as a BBC survey showed 14% of the teenagers asked had had a bad experience online.
The BBC Radio 1 and 5 live survey of 1,000 people aged 13 to 19 also showed 52% of them would accept a friend request on Facebook from someone they did not know directly, while 29% thought their reputation had been damaged by something they had said or shared online.
Children's charity leaders said many voluntary groups had been forced to cut staff or resources because of public sector cuts.
Mr McKeever, whose organisation represents rank and file officers in England and Wales, said he feared the government's plans to cut 20% from police forces over five years would have a harsh impact on educational work officers undertake.
He said: "I'm hearing anecdotally that money is being concentrated on the front line.
"We're expecting work in schools will have to be cut back."
A spokesman for the Home Office said: "As CEOP has made clear their budget settlement is manageable, allowing them to maintain staff numbers and continue working with forces to protect children."
Alan Earl, a member of CEOP's education advisory board who also worked on child abuse investigation Operation Ore, said outreach work being done to protect children online was already being affected.
Mr Earl, who works with Avon and Somerset Police and internet safety charity the South West Grid for Learning, said: "Cuts [to police force budgets] mean funds are restricted.
"The whole issue of internet safety is growing but how you deal with it is not growing.
"I've had to say to schools, 'we'll come and deal with an issue' but we can't be as proactive as we were - we can't send officers into schools any more to do talks."
He added: "We need to teach young people about their digital footprint and what effect their actions online can have."
Tuesday marks Safer Internet Day, an annual event designed to encourage people to use internet technology more responsibly.
This year it coincides with the week-long BBC Share Take Care campaign, in partnership with the UK Safer Internet Centre, to raise awareness of issues surrounding safeguarding reputation online.
Peter Davies, chief executive of CEOP, said the organisation's own budget would need to be reduced by 10% over four years.
He said: "Public sector austerity is obviously a concern as a whole range of bodies might reduce their reach just at a time when the risk is growing."
Mr Davies said that although police force budgets had been cut, senior detectives he had spoken to had indicated child protection was among their "top priorities".
Last year, councils in England faced cuts of up to 9.9% in their government funding.
The Local Government Association warned at the time that councils faced a challenge to fund child protection services.
John Carr, internet adviser to the Children's Charities' Coalition on Internet Safety, said: "I cannot think of a single organisation that hasn't been hit by the reductions in public expenditure or by the falling off in donations from the public because of the straitened times we are all in.
"How each group manages this situation will vary enormously, depending on the nature of the service they provide and the skill of their management.
"It's hard to believe this will not have consequences somewhere along the line."