The Taoiseach's shock decision to include the firebrand Sunday Independent columnist in his list of nominees to the Seanad is the culmination of a long and winding political journey that has seen Harris variously embrace republicanism, Marxism, unionism, Democratic Left, Fine Gael, the UUP, and finally Bertie Ahern over the past four decades of what has been an extraordinary career.

His elevation will certainly provide a much needed spark to the long-ignored upper house, although nobody seriously believes that was the reason for his appointment by Ahern. Trying to get inside the head of the Taoiseach is an extremely hazardous business, but it seems beyond doubt that Harris's evangelising performance on Ahern's behalf on The Late Late Show the weekend before polling was a major factor in his Seanad nomination.

It was a vintage Harris performance . . .highly articulate, charismatic, brooking no argument and infuriating his many critics in the media who would certainly not share his views on the Fianna Fail leader, particularly in the wake of the Bertie-gate revelations.

It is indicative of the many twists and (u)turns in his views over the years that there was scarcely a raised eyebrow that Harris had decided to give his backing to Ahern. But once upon a time, the notion of him endorsing any Fianna Fail leader would have seemed unthinkable.

One of the leading intellectual forces in the Workers' Party and its predecessor Official Sinn Fein, Harris's 1975 pamplet 'Irish Industrial Revolution', written with Eamon Smullen, was regarded as hugely influential in shifting the movement away from nationalism. It blamed Ireland's problems on a "lazy and greedy" native bourgeoisie, not imperialism, and regarded foreign multinationals as a good thing for the industrial working classes.

By the mid-1970s, Harris was also one of the most controversial figures in RTE, which he had joined in 1966. The extremely bright UCC graduate . . . he got a first-class honours in history . . . developed into one of the central figures in shaping current affairs at the station. Harris would have been one of those who believed that RTE's early coverage of the Troubles had been simplistically pro-nationalist. But the criticism then was that the station went too far in the other direction, amid allegations that a Workers' Party clique was dictating an anti-nationalist tone of current affairs during the late 1970s and early '80s. Debate still continues as to whether this was an exaggeration, but there was certainly considerable ideological tension and divisions within the station.

Harris had moved out of mainstream current affairs programming some time before this, but he remained highly influential in the RTE branch of the Workers' Union of Ireland, which organised producers. Its meetings often became intellectual slugging matches and there was particular strife over Section 31 of the Broadcasting Act, which banned interviews on RTE with paramilitary organisations. Harris was strongly in favour of section 31, while one of the producers to take the opposite view in those union meetings was Alex White, who is also a member of the new Seanad (watch this space).

Harris produced a controversial document, 'Television and Terrorism', in which he argued that terrorism could not be defeated by even the toughest of journalistic questioning. That document also produced the memorable phrase "hush puppies" to describe journalists whom he alleged were fellow travellers of the IRA. A colleague at the station at the time recalls that "Eoghan was part of a group that was constantly driving agendas and politicking. He was a very brilliant person, a demagogue, but hugely divisive and he would be extraordinarily aggressive with those who disagreed with him. He had very strong supporters and very strong detractors." Another person who knew him back then agrees, complaining there was never any effort to persuade or win over: "The last thing you'll ever hear Eoghan Harris say is 'that's a fair point you have there.'" Harris left RTE in 1990 and his involvement with the Workers' Party was close to coming to an end also. His undoubted flair for promotion was evident in his decision to hire fashion photographer Mike Bunn to produce the imagery for Proinsias de Rossa's successful 1989 European Election campaign. The result, an iconic black and white picture of de Rossa standing in front of the twin towers at Poolbeg, was genuinely ground breaking.

A year later, further evidence of Harris's outstanding abilities came when he produced his highly prescient pamphlet 'The Necessity of Social Democracy', which correctly concluded socialism would not survive the fall of the Berlin Wall. However, the document met with resistance in the Workers' Party and a frustrated Harris left the party. Other opportunities quickly presented themselves. Harris famously created the template for Mary Robinson's stunning presidential election campaign in the autumn of 1990.

While others involved in the campaign have since played down his involvement, there is no question the 10-page memo he produced for Robinson was genuinely innovative and extremely savvy.

Fine Gael was Harris's next port of call when John Bruton asked him to work as media advisor. However, his involvement with Fine Gael is best remembered for the PR disaster of the infamous Twink sketch, which was used as a warm up at a special party conference. The 10- minute cringefest, written mainly by Harris and featuring Twink as a cleaning lady, was broadcast live on television. It bombed, with the extremely risque humour causing considerable controversy and plenty of negative headlines for the party.

Harris also became involved in the 1997 Presidential Election. He was an advisor to the campaign of Derek Nally, but is best remembered for his description of Mary McAleese as a "tribal time bomb." While some have tried to argue that this comment was borne out in 2005 by McAleese's gaffe when she compared the Nazis' hatred of Jews with how Catholics were viewed in the North, it was out of tune with the national mood at the time. McAleese won the sympathy vote and the election. More recently, Harris was an advisor to then Ulster Unionist leader David Trimble and addressed the party's 2003 conference.

Outside of politics, Harris has enjoyed a high profile as a 'no-punches-pulled' columnist with the Sunday Times and, subsequently, the Sunday Independent.

He hasn't been afraid to adopt unpopular stances, for example strongly backing the war in Iraq. And the years haven't mellowed him . . . one former colleague described him this weekend as a "quintessential grumpy old man." He recently stormed out of the Today FM studios after a heated row with Fintan O'Toole on Matt Cooper's Last Word radio show. But everyone agrees he can write and, while his columns can be somewhat volatile, they are often highly entertaining. He is also a well respected scriptwriter, with successes including the critically acclaimed Carlton TV drama series Sharpe. Not surprisingly, given his skills as a communicator, he is also a highly regarded lecturer at the Irish National Film School.

His marriage to Sunday Independent deputy editor Anne Harris ended some years ago but the two remain on good terms. He has been spending an increasing amount of time in his beloved West Cork, but that might have to change with his new Seanad responsibilities. He sounded generally thrilled at the prospect after the announcement . . . hardly surprising, say colleagues, who describe him as a "political animal who eats, sleeps and drinks politics."

Despite his recent support for Ahern, some of those who have worked with him in the past are this weekend warning that Harris always ultimately falls out with those to whom he gives his support.

"This will end in tears, " one predicted. But even his critics have to concede that the Seanad will be a lot, lot more interesting for his presence.

CV

Born: Cork, 1943
Occupation: columnist, lecturer, scriptwriter; and, now, Senator.
Married: formerly married to Anne Harris . . . they have two daughters In the news: Because Bertie Ahern made him a senator in his Taoiseach's Eleven list on Friday