The Government faces a legal challenge over important aspects of its counter-terrorism strategy in the High Court later.
Salman Butt, a campaigner on Muslim issues, is seeking to have parts of the Home Office's Prevent strategy, including how extremism is defined, rewritten as it infringes on freedom of speech rights.
In September last year, Mr Butt was named by the Government as being a "non-violent extremist" among a group of public speakers who expressed "views contrary to British values".
His name appeared in a No 10 press release on tackling extremism in universities and colleges that linked radicalisation in educational institutions to a number of high-profile terror plots.
Mr Butt told the website Islam21C: "Many people will be eager to see the hidden and murky processes by which individuals are tarnished with the label of 'extremist', so that these issues are forced into the open and to the scrutiny of the courts."
Human rights lawyer Saimo Chahal QC told the BBC Mr Butt's challenge was a test case.
"The Prevent duty guidance issued to higher education institutions is flawed because it conflicts with the right to free speech which is enshrined in the Education Act for higher education institutions.
"The challenge, if successful, could have major implications for the controversial policy as it applies to universities and higher education."
A Home Office spokesman said they would not comment on ongoing legal proceedings.