Government guidelines to local authorities suggest that vouchers should be checked for forgery by rubbing the specially-treated paper between the thumb and forefinger.
If the vouchers are genuine, body heat then turns the words "nursery education" from pink to off-white. But the plan has already hit a snag. Some cold-fingered teachers are finding that even determined rubbing fails to produce the required effect.
Teachers are also complaining that administration of the scheme is bureaucratic enough without adding another task, however small, to their burden.
There are five vouchers per term for each child so teachers at school with 100 four-year-olds will have to thumb and finger check about 1,500 vouchers a year. Warm-fingered teachers will be able to complete the forgery test in a few seconds, but their cold-fingered colleagues may take much longer. Mark Fletcher, a nursery teacher at Shakespeare primary school in Leeds, and member of the campaign against nursery vouchers, said: "I got the voucher to change colour quickly, but my head teacher was rubbing for at least a minute and nothing happened."
The suggested forgery test comes at the end of a list of checks outlined by the Department for Education. Schools need to check that parents have signed the voucher, to sign or stamp each parent's voucher, write down the number of vouchers they are claiming on a form and keep all counterfoils for their records.
"It's very simple," a department spokeswoman said.
But Margaret Hodge, Labour's early years spokeswoman, said: "This is another example of insanity in the ludicrous voucher scheme. Teachers should be teaching children not rubbing bits of paper."
The department spokeswoman added: "We are not telling teachers they have to test the voucher. It's just if they suspect forgery ... The vouchers have been printed in such a way that the design on the back won't photocopy and is very difficult to print."Reuse content