As a member of SML's executive committee, he was heavily involved in the discussions with some smaller groups on the left that led to the formation of the Scottish Socialist Alliance (SSA) in 1995.

Fox was the SSA's East of Scotland organiser, a role he continued to play when the Alliance morphed into the Scottish Socialist Party (SSP) in 1998.

But above all, it was the role the party played in the huge movement against the Iraq War that cemented the SSP's place in Scottish politics.

Winning by just 68 votes out of 300,000,[11] Fox was famously captured on TV hurtling across the floor of Meadowbank Stadium in Edinburgh when his result was finally declared.

He presented a Member's Bill, one of only six to get to the debating floor that session, to abolish National Health Service prescription charges in Scotland.

The bill won the backing of the parliament's health committee, but was eventually voted down by Labour, Conservative, and Lib Dem MSPs.

Sheridan, the party's then national convenor, chose to sue a tabloid newspaper in November 2004 over stories it published about his private life.

Sheridan's decision to sue the News of the World, against the advice of the SSP executive committee, led to it demanding his resignation as convenor.

[15] Fox was subsequently elected SSP national convener in Sheridan's place, defeating Alan McCombes by 252 votes to 154, but the damage done to the party by the Glasgow MSP was substantial.

In response to Tony Blair's plans to bring in variable top-up fees at English universities, Fox commented that previous student politicians, such as Jack Straw and Charles Clarke, "were only able to be active in student politics because they didn't have £10,000 of debt hanging round their neck and they didn't have to rush off to work in McDonald's".

As a consequence, he was suspended from the Scottish Parliament for the whole of September and the salaries of the party's four MSPs and their staff were stopped—the severest penalty meted out to any peaceful protest in British parliamentary history.

September’s referendum has energised people to a remarkable extent with debates on the 'democratic deficit' at the heart of Scottish politics now taking place in households, schools, workplaces, village halls and urban community centres from one end of the country to the other.

"[30] When the make-up of the Smith Commission was announced after the rejection of independence, Colin Fox protested the decision to "uniquely exclude" the SSP from proceedings.

He wrote to the Smith Commission: "The argument some use to justify our exclusion on the grounds that we currently have no 'parliamentary representation' fails to appreciate that the referendum was not a parliamentary process but an unprecedented public debate that resulted in an extraordinary level of engagement from all sections of society.

[37] He was asked to run for the position by members of St Andrews-based student groups such as Stop The War, due to his previous experience with the pro-peace and social justice movements.