More than 20,000 scientists have have signed a demand that journal publishers grant them free online access to research papers.
Nearly 800 United Kingdom scientists have signed up to the Public Library of Science, which advocates an online public library for research in medicine and the life sciences.
An open letter states that, from September, the signatories will only publish in, edit or review articles for journals that grant free distribution rights six months after they are published.
The research should be available through public resources such as the North America-based website PubMed Central, which publishes free peer-reviewed papers from 15 journals.
The scientists said the library would enhance scientific productivity by integrating disparate research communities. They said publishers would remain in business if they charge for the first six months after publication.
The initiative, set up by 12 academics, mostly American but including Cambridge geneticist Michael Ashburner, is based on the high-energy physics e-Print Archive, set up at the Los Alamos Laboratory ten years ago.
Toby Bainton, of the Standing Conference of National and University Libraries, supported the model. He said it would give journal publishers business while opening access to the literature.
Robert Campbell, president of journal publisher Blackwell Science, dismissed the model as shortsighted and said that free access could undermine the finances of journals, leading to lower standards and even their demise.
University librarians have continued to veto Nature online. They complained the licence costs 20 times the paper subscription with a three-month delay for news and analysis. Nature has decided to supply all sections immediately on publication from May 1.