Councils across Wales have warned schools to prepare for budget cuts of around 16% over the next three years, a teaching union has said.

UCAC has told BBC Wales the move would be "devastating" for schools and the standard of education they provide.

The Welsh government has sought to protect schools' budgets, as its own funding from Westminster has fallen.

Welsh ministers said they would set out their spending plans for 2016-17 in their draft budget, on 8 December.

Speaking on Radio Cymru's Post Cyntaf, Rebecca Williams from UCAC, said: "What we're hearing from local authorities is they're preparing their schools for cuts in the region of 16% over the next three years.

"If that's true it would be really devastating for schools and the standard of education that they can provide to children and young people.

"The impact would be severe because the only way you can make that level of cuts is by making staff redundant."

Media playback is unsupported on your device Media caption Rebecca Williams said the estimated scale of the cuts could lead to job cuts and bigger classes

Gethin Thomas, head teacher of Ysgol Gymraeg Dewi Sant in Llanelli, confirmed that Carmarthenshire council had told his school to expect a 16% budget cut.

"If we look over the next three years, there could be a cut in out budget of £250,000," he said.

"Redundancies are obviously something that we will have to focus on.

"No school, I think, in Carmarthenshire would have the reserves to pay for the cuts that we are faced with."

'Implications'

The overall level of reserves held by schools in Wales was £64m on 31 March 2015, the equivalent of £141 per pupil.

This is an increase of 6.6% compared with 2014, but that year's figure was the lowest since 2001.

A Welsh government spokesman said: "Following the Spending Review we will consider the implications for Wales before setting out our own spending plans for 2016-17 in our Draft Budget on 8 December."