It comes as the House of Lords begins debating the NHS reform plans today before voting on whether the Health Bill should be withdrawn on Wednesday.
The largest RCGP survey yet of GP opinion on the reforms shows just 4% of respondents think the reorganisation would result in better care for patients.
The poll of 1,900 GPs also indicates that support for involvement in clinically-led commissioning has dwindled over the past three months.
A previous RCGP survey in July showed 62% of GPs did not want to be involved on the board of a clinical commissioning group (CCG), but the latest survey now shows that figure to be 68%.
It also shows around seven in 10 GPs feel they will not have sufficient time to be involved in CCG activities, while two thirds say they don't think they have been sufficiently resourced to carry out the role.
RCGP chairwoman Dr Clare Gerada said the results of the survey are ‘impossible to ignore’.
She said: ‘The survey confirms what we have been saying all along; the college has made its support for placing GPs at the heart of the health service clear, but ...the majority of respondents still have concerns about commercialisation, increased bureaucracy and standards of patient care that the government has not allayed.
‘With the Bill making its way through the House of Lords, it is important that peers have as much information as possible so that they can ask the relevant questions, and make informed choices about what happens next.’