Former prime minister David Cameron created the cross-departmental childcare implementation taskforce in June 2015. But leading early years organisations believed it had been disbanded, after having no contact with the group.
London Early Years Foundation chief executive June O'Sullivan said she had received no correspondence from the group, and was unaware of its remit, despite having meetings with childcare minister Caroline Dinenage.
"None of us have heard from it and we're the main providers," she said.
"[Government] policies at the moment are creating operational problems, such as recruitment. The only way to solve them is in collaboration [with the sector]. Change is not going to happen without our engagement."
National Day Nurseries Association (NDNA) chief executive Purnima Tanuku said her organisation has had no contact with the taskforce as a group.
"Now is the time for the taskforce to step up its profile," she said.
"It has a lot of work still to do to make 30 hours a success, with only seven months to go until full roll-out."
Pre-school Learning Alliance chief executive Neil Leitch also questioned the activities of the taskforce.
"We are concerned about the lack of consultation between the taskforce and the sector, not to mention the lack of information available regarding the taskforce's meetings, actions and efficacy," he said.
"If this government is serious about improving childcare infrastructure and developing future-proof policies that work for providers, parents and children, then it needs to embrace transparency and further involve the sector in the policymaking process."
Two MPs have written parliamentary questions asking when the taskforce has met and what attendance has been, but on both occasions they were denied the information.
In response to questions by Lucy Powell in October 2016 and Jess Phillips the following month, the government said that information relating to the proceedings of implementation taskforces, including when and how often they met, "is not disclosed as to do so could harm the frankness and candour of internal discussion".
The Department for Education told CYP Now that the membership of the implementation taskforce changed in October 2016 following a cabinet reshuffle, adding that it continues to operate.
A spokeswoman said: "The childcare taskforce is committed to driving the delivery of a government-wide childcare offer to support parents to work."
She was unable to provide details of when the group last met.
The childcare taskforce has been tasked with overseeing the delivery of government efforts to provide 30 hours of free childcare a week to all three- and four-year-olds by September 2017.