Jacqui Lait, Tory spokeswoman on civil society, told a charity investment conference: "I think there are difficulties with this Bill and these should be examined very carefully. Then we will decide then what we do and don't like."
Her remarks came as the Parliamentary committee scrutinising the Bill produced a report that papered over MPs' disagreements about how it should deal with the controversial question of defining public benefit.
The committee's formula of leaving the definition to the Charity Commission, while also making provision for ministers to issue guidance, echoes a 'concordat' issued by the Home Office and the commission which was produced to reassure the committee that public schools would not escape demonstrating public benefit.
If the Government follows that formula in the real Bill, it risks hardening threatened opposition by Conservatives, who dislike the idea of ministerial guidance. Stuart Etherington, chief executive of the sector umbrella body, the NCVO, also said he was not convinced by the need for guidance.
If the Government drops the idea of guidance, this could reawaken the opposition of some its own MPs who feel that if the definition of public benefit is left to the commission and the courts, private schools and hospitals might evade the requirements of public benefit tests on the basis of existing case law.
The publication of the report produced upbeat reactions from the Home Office, the Charity Commission and the main sector organisations. Hopes are now high that the Bill will be included in the Queen's Speech next month.
However, backbench rebellion or a partisan split could hamper its passage through Parliament in a session already expected to be curtailed by the next election.
As the Conservative conference opened in Bournemouth, Lait told Third Sector that the party would make a policy statement for the sector later this year. "If we announce it at the conference, it'll get lost in all the other announcements," she said. "We think the sector is too important for that."