Sarkozy's (anti-immigrant, anti-European, anti-gay) crony

France's anything-but-red baron, Philippe de Villiers, has described President Nicolas Sarkozy as an "imposter", "a liar" and a "Duracell bunny". That was in the distant, political past – a couple of months ago.

Next month Viscount de Villiers – a virulently anti-European, anti-immigrant, anti-gay populist and Catholic fundamentalist – will become the latest addition to President Sarkozy's political menagerie, stretching from the soft, well-meaning left to the borders of the far-right.

Mr de Villiers, or Vicomte Philippe Le Jolis de Villiers de Saintignon, has let it be known that he expects to sign up in September for Mr Sarkozy's "electoral coordinating committee" for the regional elections next year and, implicitly, for the next presidential election in 2012.

The president's tactical motives in bringing Mr De Villiers, 60, into his broad political coalition are clear enough. With more than half his five-year term still to go, Mr Sarkozy is mocking the divided French left by tightening his effortless control over the right and centre. By allying himself with the Catholic conservative De Villiers, the twice-divorced, half-foreign, non-church-going president is reassuring the many traditionalist, haut-bourgeois voters who support him but mistrust him.

Ideologically, however, the new alliance is bizarre and, to some of the president's supporters, disturbing.

Mr Sarkozy likes to present himself as a pragmatic pro-European, the saviour of the Lisbon treaty on EU reform and a man determined to break down social and racial barriers. Mr De Villiers is a Europhobe, the man who coined the phrase "Polish plumber" to describe the alleged threat to France from the Lisbon treaty and European enlargement.

Although avoiding (just) the outright racial fear-mongering of Jean-Marie Le Pen, Mr de Villiers often makes exaggerated claims about the "islamisation" of France. He has accused Islam, not just radical Islam, of being engaged in a de facto "war" with the West. ("Islam is the breeding ground of radical Islam and radical Islam is the breeding ground of terrorism.")

He is also a vituperative campaigner for "family values" and against gay rights. France's successful civil partnership law or PACS which allows gay partners – and others – to make formal commitments to one another, is, he says, a "return to barbarism".

For 28 years, Mr de Villiers has manoeuvred on the fringes of the traditional right without ever creating a personal following of more than 4 or 5 per cent of the electorate.

But Mr de Villiers has justified his decision to join forces with Mr Sarkozy as the best way to move his ideas from the margins of French politics into the heart of government. There are rumours, not yet denied by the Elysée Palace, that President Sarkozy may be considering a junior ministerial role for Mr de Villiers.

So far President Sarkozy has handled his policy of "ouverture" to politicians of the moderate left and centre reasonably well. There are fears, both inside and outside the government, that reaching out to Mr de Villiers may be a bridge too far.

The league against racism and anti-Semitism, Licra, has protested that the president's new alliance amounts to a "back-dated justification" of "intolerable racist remarks" made by Mr de Villiers in the past. To keep its new ally happy, the league predicts, Mr Sarkozy's own party, the Union Pour un Mouvement Populaire (UMP), will have to push its own rhetoric and policies "to the right or even to the far right".

Philippe de Villiers descends from the Orléans branch of the French royal family. In the early 1960s, his father, Jacques de Villiers, was linked to the OAS, the right-wing terrorist movement which campaigned to keep Algeria part of France and tried to assassinate President Charles de Gaulle.

The family comes from the Vendée, the département just south of Brittany which revolted against the French Revolution and remains fiercely catholic-conservative. As a young man, Mr Philippe de Villiers was a senior civil servant and then an entrepreneur, setting up radio stations and – in 1977 – a live spectacle arena and theme park at Puy du Fou in the Vendée, which was extremely successful. The shows are usually dedicated to France's glorious, royalist, conservative, pre-revolutionary – and pre-democratic – past.

After flirting with the mainstream right for a decade, he created his own political party, the Mouvement pour la France (MPF) in 1991. The high points of his political career (to date) were, 4.7 per cent of the vote in the first round of the 1995 presidential election and, jointly with Charles Pasqua, 13 per cent in the 1999 European elections, defeating a more moderate right list led by Mr Sarkozy.

Mr de Villiers has been a Euro MP on and off ever since and has often been named as the least active, and one of the most absent, members of the European assembly.

Mr De Villiers campaigns for low taxes, no immigration, no mosque-building, no gay rights and for policies to encourage and reinforce the traditional family. His symbolic status as an anti-gay family man, with seven children, has been damaged in circumstances which remain somewhat opaque. His son Laurent, 24, has accused his older brother, Guillaume, 29, of having repeatedly raped him when he was a child. The accusation was withdrawn last year and then renewed in January. A legal investigation is under way. Mr De Villiers claims Laurent has been "manipulated" to damage his career.

Sarkozy supporters on the moderate left and even on the right have been puzzled and angered by his decision to reach out to Mr De Villiers. Tactically, the viscount's support could give the president two to three per cent extra votes in the first round in 2012 – enough to give Mr Sarkozy unstoppable momentum into the second round. But his presence in the president's broad coalition may be a damaging source of incoherence and embarrassment. With the left still scattered and leaderless, why bother?