The National Childminding Association for England and Wales met education ministers Robin Squire and Lord Henley in June, but is still waiting to hear whether its members will be allowed to take the Pounds 1,100 vouchers issued to the parents of all four-year-olds.
The association, which meets in Exeter tomorrow for its annual conference, plans to take the Government to the Office of Fair Trading if it refuses to lift the ban.
The two Scottish childminders, who live in rural areas of Argyll and Bute, wanted to become part of the nursery voucher scheme because there are no local nurseries or playgroups.
It is understood that the two, who both have assistants, are already trying to educate the children in their care and do not plan to change what they offer for the sake of the voucher.
Maggie Simpson, national development officer for the Scottish Childminding Association, said: "It was not difficult to persuade the Scottish Office to accept them. We already have a good relationship with them so a lot of the networking was already there. We also had a lot of support from other Scottish pre-school groups."
But she stressed that the SCA would not be encouraging all childminders to apply for nursery vouchers because it did not want to force them into competition with local education authorities, and, anyway, some childminders did not want to join in.
Gill Haynes, chief executive of the NCA, said: "We have had sufficient response from Norfolk [a voucher pilot authority] which shows that childminders will be passionate about being left out."
She said childminders should not be banned because they often had only two four-year-olds as some playgroups only had four.
The NCA will debate its Childminding Manifesto in Exeter. It wants the Government to recognise high-quality child care by strengthening the guidance in the Children Act. It also wants free compulsory training for all childminders before they are registered and improvements in the annual inspection programme, with additional visits during the year.
This week 25 MPs visited childminders as part of the Childcare Umbrella's campaign to show politicians how they help the local economy by supporting parents in employment.
One of the 25 was National Heritage Secretary Virginia Bottomley, who was welcomed by Farnham Childminding Group at their regular drop-in meeting this morning.