For many people Sile de Valera is frozen in time: she is the young blonde woman with the big surname who burst into Irish politics in the late 1970s to expose her party's split personality on Northern Ireland with a series of potent republican speeches. Her arrival contributed to the demise of Jack Lynch and his replacement by Charles Haughey.

However, suspicion that she had been acting on behalf of Mr Haughey to destabilise Mr Lynch died when her speeches continued after the change. "Sources close to" Mr Haughey were prompted to tell her through the media to shut up or be fired.

And just as she was speaking her mind then, trying to reclaim her grandfather's party from revisionists and compromisers, so too she was doing it again this week, questioning the role of the "Brussels bureaucracy" and the wisdom of giving it more power in Irish affairs.

Immediately after her speech to a US audience, conspiracy theorists suggested she had been sent out by cunning, devious Bertie Ahern to fly a kite and win the party a few Eurosceptic votes. But there is no evidence for this.

Her speech did not come from nowhere. In 1979 she questioned publicly the idea of European political union. Since 1997 she has been involved in a standoff with Brussels, refusing to designate Special Areas of Conservation under the EU Habitats Directive until the landowners involved had had a chance to appeal. The European Commission is expressing impatience with the slow progress. Her speech reflected her experience, and Mr Ahern knew her views long before this week.

However, it came as a surprise to most people that she had a position on these matters. After an extraordinary series of dramas in her early political life - including a career-threatening period of three consecutive election losses - de Valera became a politician who largely kept her thoughts to herself. At one stage when she resigned the Fianna Fail whip over the ending of the Shannon stopover, several colleagues reported people remarking that they were not aware she was still a TD.

It was so different in the early days. Elected to the Dail as a 22-year-old for Dublin mid-county in 1977, in September 1979 she spectacularly exposed deep divisions within Fianna Fail over what its republicanism now meant in the context of the murderous violence in the North.

Her speech in Fermoy, Co Cork, at the commemoration of Liam Lynch - an IRA chief of staff killed in the Civil War - called on then Taoiseach Jack Lynch to "demonstrate his republicanism".

Filled with quotations from Padraig Pearse and citations of past republican heroes, the speech was seen as having a simple, barely coded message: Jack Lynch had gone soft on the national question and was leading the party away from its traditional aim of seeking a united Ireland, the aim for which her grandfather had founded the party.

Mr Lynch publicly rebuked her, but the speech marked the beginning of the final onslaught on Mr Lynch's leadership. Within two months Lynch had resigned, and was replaced by Haughey, long the great hope of the greener wing of the party.

Within a year, de Valera had disproved those who believed she had been acting as a stalking horse for Mr Haughey. In a speech during a Donegal by-election campaign she accused the then British Prime Minister Margaret Thatcher of callousness, insensitivity and hypocrisy over the handling of the H-block hunger strikes.

Haughey disowned the speech almost immediately. Undaunted, Ms de Valera later virtually called for support for IRA hunger striker Bobby Sands in the Fermanagh-South Tyrone by-election and then welcomed his election. She condemned Thatcher again over her intransigence, she visited Sands in the Maze prison and accused Garret FitzGerald of having a "Free State mentality"

She was being consistent. In January 1977, before she ever ran for public office, she gave one reason for having joined Fianna Fail at the age of 18: "It was simply that I had an aim, which was and is to help bring about a united Ireland."

There was nothing simple about this in the Ireland where traditional nationalist attitudes were being seriously challenged under the government of Liam Cosgrave. It was the government that included Conor Cruise O'Brien and Patrick Cooney, who used intellectual argument and special legislation to take on violent republicanism and traditional nationalist doctrine.

The stage was set for the arrival of Sile de Valera, young carrier of the true republican flame in the struggle against those who would lead the State away from its traditional self-definition.

With her advisers, including Adrian Hardiman, now a Supreme Court judge, de Valera positioned herself as the polar opposite of the revisionists: "No matter how hard the present government may try," she said in an interview with this newspaper before her election, "they can never break that nationalistic feeling that is embedded in the Irish people. The Government's attitude to the problem only lives up to their reputation as Free Staters."

Her national profile was enormous, and throughout the State she was cheered by substantial sections of Fianna Fail wherever she went. However, her redrawn Dublin South constituency contained more than its share of those revising their nationalist outlook. She lost her Dail seat in 1981 and in February 1982 failed to regain it.

She moved to Clare for the November 1982 election and lost again by just a couple of hundred votes. When her term in the European Parliament ended in 1984 she was effectively out of full-time politics.

She then devoted herself to winning a seat in Clare, buying a house, setting up a constituency office in Ennis and travelling there every weekend. At the same time she obtained a qualification in career guidance and another in psychology. She said she would call it a day if defeated in 1987, but she was successful, topping the poll. She has been re-elected in the three elections since.

She grew up in Cabinteely on Dublin's south side, a daughter of the High Court Taxing Master Terry de Valera. She was educated at Loreto Convent, Foxrock, graduating from UCD with a BA degree in history and politics in 1976. After doing a Higher Diploma in Education she did her teaching practice at her old school.

After her dramatic first phase on the political scene, her second coming was as an extraordinarily low profile deputy for eight years. Her appointment to Fianna Fail's front bench in 1995 and to Cabinet in 1997 caused surprise. Geographical considerations played a part, but it is unfair to say that her seniority is due solely to this. While she has failed to raise her public profile substantially she has shown she has an impressive work rate.

In relation to the arts, she has a clear idea of what she wants to do and has pursued her view with persistence. She says her twin aims for the arts are "excellence and access", but her critics say she has pursued the latter at the expense of the former. They say her view is parochial: her response is that she is ending the monopoly of the "Dublin-based elite" over the arts.

Most accept that she has done well in getting money for the sector - many in the arts would like it if the Minister confined herself to this role. She has just completed a review of all arts legislation, and seems to be planning changes. Her proposals suggest that her Department, and not the Arts Council, should make arts policy, which alarms some in the arts community who shudder at the idea of direct political control of the arts.

In the area of broadcasting there is less sign of dynamic activity. Her Bill to allow for digital television is considerably behind schedule - held up partly by a dispute with RTE over control of the transmission system. She has also prevented RTE from having its licence fee index-linked. As RTE continues to struggle financially, the hoped for indigenous commercial competition - TV3 - has become a foreign-owned entity, using foreign content to compete with the national broadcaster.

She is courteous, friendly and pleasant - people who think they will dislike her because of her stance in the late 1970s and early 1980s come away from meeting her with a very different view. She is not a visible socialiser on the Dublin political scene, devoting most of her life to politics.

This includes a very high commitment to constituency work in Clare, where the concept of a safe seat remains largely theoretical. The Special Areas of Conservation were particularly controversial in parts of Co Clare, where traditional turf cutting had to stop once land was designated. As Minister, she had made compensation available for such cases.

While she made a rare foray into international politics this week, she knows all too well that, ultimately, all politics is local.