Analysis by the Pre School Learning Alliance of funding rates set to be provided to childcare settings in five local authorities taking part in trials from September found that they will receive existing levels of funding the first 15 hours and slightly more for the second 15 hours.
However, the Pre-school Learning Alliance said that, in light of childcare minister Sam Gyimah previously stating that the national roll-out will involve higher funding rates for all 30 hours, the trial risks failing to reflect how the scheme will work in practice from 2017.
The organisation added that there is a "real danger" that by offering two separate rates, a "false dichotomy" is being created between the first 15 hours of "early education" and the subsequent 15 hours of "childcare".
Neil Leitch, chief executive of the Alliance, said the funding situation calls into question the value of the pilot.
“When the minister said that the additional 15 hours would be funded at the same rate as the first, we assumed – in good faith – that this would apply during the 30-hours trial," he said. "So we were surprised to learn that early implementers would be in receipt of two separate rates.
“Aside from being wholly impractical, funding only the additional hours at a higher rate is misleading: when you average out the whole 30 hours, the overall increase in funding is significantly less than the sector was led to believe it would be.
"Anything less than 30 hours of high-quality early years provision would be a failure of the policy.
“Even more concerning is the fact that the government is defending this approach by saying that it only applies to the pilot scheme and may not be used when the 30-hour offer rolls out in full next year.”
Leitch added: “Given that the pilots are meant to give providers a realistic view of how the scheme will work in practice, such a statement calls into question the value and integrity of the entire trial.”
Eight local authorities will take part in the trials, one year ahead of national roll-out, offering 30 hours of free childcare to three- and four-year-olds whose parents are working.
The Department for Education has said the pilot will help inform national roll-out.
Last month, a number of nursery providers in York pulled out of the pilot, claiming they could not afford to take part under the proposed funding rates.