Election officers have hit back angrily at calls from the education secretary for general election polling stations not to be placed in schools.
Gavin Williamson wanted to avoid disruption to school nativity plays and Christmas concerts, which could clash with the 12 December election day.
But election officers have written to the education secretary to express their "extreme disappointment".
They say in many areas there are "no alternatives" to using schools.
This week Mr Williamson wrote to returning officers telling them that councils would be funded to find alternative venues for polling stations - and not to use schools as places to vote.
He said he wanted to make sure that "long-planned and important events" in schools at Christmas, such as plays and carol concerts, would not have to be cancelled.
But the announcement has prompted anger from the Association of Electoral Administrators, which is the professional body representing people who run elections.
In a stinging letter to Mr Williamson, they accuse him of a "complete lack of knowledge and understanding".
"We question why this letter was sent out so late, after most polling stations have already been booked," say the election officers, who warn that arranging a December election at short notice is already challenging enough.
They reject Mr Williamson's claim that "every community" will have alternative venues for voting, so that schools will not have to be used.
"That is simply not the case. In many parts of the United Kingdom, including towns and cities but especially in rural areas, there are simply no alternatives to the venues designated as polling places," says the letter from the association.
Chief executive Peter Stanyon says the process of deciding where to locate polling stations has mostly taken place - and the data has been sent to printers for polling cards.
He says schools are used as polling stations because they are well-known local venues and are likely to be accessible for people with disabilities - and often there are not any other practical options.
The move not to use schools for polling stations had been backed by head teachers' leader Geoff Barton.
He said many schools would have Christmas events scheduled - and he questioned whether schools were really "suitable venues" for voting, particularly when elections had become more frequent.