The Adult Learning Inspectorate fears Excalibur, which received 22,000 hits on its website last month, will be axed if it has to join forces with the Office for Standards in Education.
The ALI set up Excalibur two years ago as a quality improvement service to guide colleges through the inspection process by enabling them to share good ideas.
It expects a new body set up as a result of a merger with the Office for Standards in Education will have no brief for quality improvement.
A four-month consultation begins in September to consider plans to merge the inspectorates as part of the Government's desire to reduce the number of national public-sector inspectorates by 11 to four.
The consultation will consider three options: to keep things as they are, to merge into a larger single regulator for education, or for the ALI to no longer remain as a quango but to become a "public-interest company".
The last option is preferred by the ALI. It would mean that the service would work under contract for Government departments and private training companies.
This is a similar model to the one which governed the Training Standards Council, the organisation which preceded the ALI.
The ALI'schief inspector, David Sherlock, said: "If the consultation results in our preferred option, we would definitely want to take Excalibur with us. We have 2,000 people who receive alerts when something new goes on the site and last month Excalibur received an average 740 visits a day. We have not built up Excalibur to have it taken apart again. The number of providers accessing the service proves how useful it is to them."
Excalibur was set up with no additional funding from the Department for Education and Skills. It has a database in which colleges can access detailed case studies of good practice uncovered by ALI inspectors.
It also features an inspection toolkit, guiding colleges and training organisations through each step of the inspection process.