The move follows the Department for Education’s consultation on the plans in the autumn.
The Times reported that ministers were considering a range of tests, including the PIPS baseline assessment, designed by academics at the Centre for Evaluation and Monitoring at Durham University.
This is already used by some primary schools and is designed to be carried out in the first few weeks of children entering Reception.
It includes showing children pictures of a variety of objects and asking them to point to a yacht.
Jan Dubiel, national development manager for training and resource company Early Excellence, said that such tests were ‘dangerous’ and a ‘waste of time’.
‘They have nothing to do with real learning or child development, because they measure children’s experiences, not cognition,' he said. ‘It’s far more accurate, meaningful and authentic to observe children.’
He added that while he had no problem with children being assessed when they started Reception, it depended on ‘what you assess and how you assess it. It’s got to be done in a way that that ensures you get accurate, meaningful information.’
Mr Dubiel stressed that the tests would not affect the majority of early years practitioners, because they do not work in Reception, and urged them to continue to do what they already do, which is to carry out assessing children through their observations.
He also pointed to a clause in the statutory framework of the EYFS, which states that assessment should not involve ‘long prolonged breaks of interaction with children’, or require ‘excessive paperwork’.
Julian Grenier, national chair of Early Education, also spoke out against baseline tests in Reception, listing five reasons on his blog why he was against the move.
Testing young children for their ability was ‘notoriously difficult’ he said. He also highlighted that there could be up to 11 months of difference in ‘significant’ development between a child born in August, who would have just turned four at the start of Reception, and some other children who would be five in September.
Mr Grenier added that even well-trialled tests, such as the British Ability Scales had been found to be unreliable, for example for children from a black and minority ethnic background and for children learning English as an additional language.
There had also been ‘constant change’ to early years policy in recent years, such as the phonics tests and revision to the EYFS, he said, adding that the money could be better spent elsewhere.
‘Starting school is a big step for children. Many children find it stressful at first to settle in and feel confident. Testing them just sets up another hurdle, and one which is likely to cause some children considerable distress. Additionally, because the children are dealing with so many new things when they start school, the tests will not show anything like their potential.’
He pointed out that nearly all three- and four-year-olds attended early education places and that children’s development was already tracked by early years providers.
‘If the problem is that there are not proper arrangements for the transition of children from nursery to Reception, why not address that problem rather than bring in yet another regime of testing?’
Campaigners from the ‘Too much, too soon campaign’ also criticised the plans.
In a statement on its website, campaigners said, ‘Given the considerable amount of expert opposition to the idea of baseline testing we are deeply concerned at the suggestion that it might still go ahead.
‘We will wait to see the Government’s formal consultation response, but fear that yet again it is prioritizing measurement and accountability over child wellbeing.’
Last September, more than 800 people from the campaign signed an open letter against a focus on 'school readiness', testing at an ever-earlier age, and the downgrading of play, which they said threatened 'profound damage' to a generation of children.
Deborah Lawson, general secretary of Voice, the union for education professionals, questioned the purpose of the tests.
'Teachers should be free to make their own assessments of children at the appropriate time. Teachers and schools do not need any further accountability measures when there are so many already in place and rigorous Ofsted inspections,' she said.
'I am also concerned that testing at such an early age could herald the lowering of school age – changing the landscape of schools and the early years sector.
'While some countries in Europe don’t start formal education until six of seven, the plan for England seems to be to start formal testing and schooling at four or even younger.
'If children are in school rather than nursery, that would reduce the cost of childcare for the state and parents, but it wouldn’t necessarily be in the best interests of children.'
A DfE spokesperson said, 'We have consulted on our proposed primary school assessment and accountability measures and we are considering our response.'