Leighton Andrews pressed for legal advice over the website restrictions
Controversial guidelines restricting assembly members publicly-funded websites have been withdrawn after legal advice said they were unworkable.
The Welsh Assembly Commission guidelines were looked at by legal experts who said the human rights act may also be breached.
Leighton Andrews, the Rhondda AM, said politicians' views were being censored and described the guidelines as absurd.
A spokesman said the guidelines would be withdrawn and redrafted.
Mr Andrews, a deputy minister in the Welsh Assembly Government, had pressed for the legal advice over the guidelines.
He said he had been contacted by 20 other assembly members who urged him to challenge the guidelines.
The legal advice said the guidelines lacked clarity or any logical basis and were unworkable.
"This is a victory for common sense and freedom of speech," said Mr Andrews.
"The guidance will now have to be withdrawn, and as a consequence all assembly members are able once again to communicate openly and honestly with their constituents, without fear of repercussion."
The guidance to AMs was being issued by the Assembly Commission, which runs the assembly and is chaired by Presiding Officer Dafydd Elis Thomas.
The guidance on AMs' websites funded by public money tried to rule out campaigning messages.
Assembly members are not allowed to use public funds to support parties or conduct business activities. This was to be extended to websites.
But the legal advice from barrister Graham Walters said: "The purported distinction between assembly business on the one hand and political activities... on the other seems to lack any logical basis and to be unworkable."
The advice also said the guidance would not satisfy article 10 of the European Convention on Human Rights.
"The rules set out in the guidance would not satisfy the requirements of article 10 because they lack clarity and certainty," it said.
"The Assembly Commission was in danger of censoring what we were seen to do," said Leighton Andrews.
A spokesman for the Assembly Commission said: "The commission's right to place restrictions on the content of AMs' websites paid for by public money has been supported by independent legal advice but legal criticism of the particular guidelines issued means that they will have to be withdrawn, redrafted and consulted on."