Joanie Chapman will be visiting Downing Street next week, but not as a tourist. The little girl, who will turn four in May, will be part of a group marching on parliament on 25 April to deliver a 64,000-signature petition opposing the introduction of a statutory test for four- and five-year-olds to be taken within weeks of starting school.

The results of the assessments, which gauge language, communication and early literacy and numeracy, will be used to track and measure children’s progress until they leave primary school.

Joanie’s mother, Angela Roy, 40, is vehemently opposed to her daughter taking the test. She will travel from near Totnes in Devon to attend the rally, organised by the campaign group More Than a Score. She believes the first few weeks of school should be about settling in.

“I want her to be bonding with her teacher, becoming familiar with the routine and with her group of peers, making friends,” said Roy. “But instead she’ll have to be taught by a supply teacher or teaching assistant while her teacher is off testing her classmates and her.

“It seems crazy that we have the government talking about young people’s mental health but at the same time they are introducing a test for our very youngest children.”

Ministers are pushing ahead with the test, known as the reception baseline assessment, despite widespread criticism. The British Educational Research Association last year concluded that it would be “detrimental to children, parents, teachers, and the wider education system in England” and produce invalid results which could not be used as a measure for future attainment.

We have the government talking about young people’s mental health but introducing a test for our youngest children Angela Roy

In a Department for Education (DfE) trial starting in September, before the rollout to England’s 20,000 primary schools next year, children will be set a 20-minute series of tasks testing their ability to count, recognise letters, numbers and everyday objects.

As pupils give their responses, teachers will record “yes” or “no” judgments on a tablet. The software will automatically convert these to marks and children will be scored out of 45. In a move to counter criticism that the tests will label children as high or low ability, the results will not be communicated to schools or parents and will be used by the government to hold every school accountable for the progress pupils make.

In the tests, four-year-olds could be shown pictures of a man, a cat and a dog, and asked to point to the picture that rhymes with “frog and log”. Pupils shown a picture of a square and a circle would be asked if they can name the shapes.

How a pupil responds to each question dictates what they are presented with next. This “routing” helps prevent the “possible discomfort” of four-year-olds facing questions that are too difficult. For instance, only a child who can read simple words would be asked to read a sentence.

Many teachers already carry out assessments to gauge a child’s starting point but they are not necessarily in the form of a test and the results are only used internally.

Beatrice Merrick, chief executive of the Early Education charity, said the test was unlikely to say anything valid about a child’s real ability: “You can ask a four-year-old what sound the word ‘parrot’ begins with and they may say ‘p’ one day and ‘squawk’ the next,” she added.

The government defends the assessment, insisting it has no pass mark, is short, and will help teachers to support children. Some headteacher groups have decided not to oppose the test as it will replace statutory tests taken by seven-year-olds, currently marked by teachers.

A DfE spokeswoman said: “Schools should be accountable for the progress of all their pupils and the reception baseline will help to provide a starting point to measure progress through primary school.”

Angela Roy, who, like parents across the country, will find out this week if she has secured the primary school place she applied for, is unconvinced: “I was watching Joanie in a playground the other day. She was filling a bucket of sand; learning about ‘full’ and ‘empty’. She made a little friend; they were cooperating, discussing, solving problems.

“That is what learning should be about at age four, not ‘can you count to 20 or write your name?’.”