The latest proposal to amend the Charities Bill comes from the shadow charities minister, Andrew Turner, who proposes to restore the presumption, introduced in 1601, that educational, religious and poverty-relieving charities deliver public benefit.
The effect of this amendment would be the exemption of private schools from a test to determine if they provide public benefit.
However, the Government remains committed to resisting any amendment to the Bill as passed by the Lords, which introduces a universal public benefit test but gives the Charity Commission the task of deciding how it is interpreted.
The commission, loath to assume the responsibility the Government wants to give it, has said it would welcome an amendment to the Bill to clarify "the ways in which the public benefit requirement would apply to fee-charging charities".
Many Labour MPs have warmed to the 2005 Scottish Charities Act provision that organisations whose fees are "unduly restrictive" should not have charitable status. The Scottish public benefit solution is now official Lib Dem policy too.
The amendment tabled last year by Lord Phillips, which would merely instruct the Charity Commission to take account of fees, seems to be losing popularity.