The institute has asked the Home Office for £1.71m for the scheme, which is due to get under way in autumn. But no sum has yet been paid.
"Self-regulation does not rely on the Charities Bill going through, but it does need the funding," said chief executive Lindsay Boswell.
"We've promised an autumn launch, but funding needs to be made available before the election period begins if we are to do this."
The institute hopes the Home Office and the Scottish Executive will finance the scheme for the first five years, after which it will become self-financing, mainly through membership fees.
Funding is needed to pay for staff to run the independent scheme, which is not linked to the institute or any other membership body.
The proposal - drawn up by a steering committee whose members include representatives from the IoF, Charities Aid Foundation, NCVO and the Charity Commission - paves the way for a single set of standards for all UK fundraisers.
This would include new rules on face-to-face fundraising, criticised by some as too aggressive.
A Home Office spokes-man confirmed the plan had arrived. "The Government has expressed its commitment to the scheme," he added.