Duncan Smith, champion of the right

Mr Duncan Smith's campaign snowballed giving him victory

When Iain Duncan Smith took the plunge and joined the battle for the Conservative leadership few would have predicted that he would have beaten his rival Michael Portillo and come second behind Ken Clarke in the final ballot of Tory MPs.

Endorsed by Lord Tebbit as "a remarkably normal family man with children", the former soldier remains the standard bearer of the party's Thatcherite-right as he prepares for the final battle of the leadership campaign.

Duncan Smith's CV

Born April 1954

Joined Tory Party in 1981

Contested Bradford West 1987

Elected as MP for Chingford 1992

Social security shadow 1997-99

Defence shadow 1999-

Early in the contest Mr Portillo was widely tipped as the favourite having secured the backing of two-thirds of the shadow cabinet before his challengers had even left the traps.

But in a twist that few, if any, predicted the momentum that characterised the shadow chancellor's early campaign fizzled out and it was Mr Clarke who won, with Mr Duncan Smith coming second.

Growing stature

His stature has grown in the last few years as those on the right of the party have become increasingly alarmed by Mr Portillo's drift leftward.

And seen from the perspective of the Tory right, Mr Duncan Smith's political credentials are impeccable.

In fact there could not be a clearer choice between Mr Clarke as an old fashioned pro-European leftwinger and Mr Duncan Smith.

A former member of the Scots Guards, he has seen active service in Northern Ireland.

He is a firm believer in the free market and a member of the Thatcherite No Turning Back Group - deserted by Michael Portillo last November.

A die-hard Eurosceptic, he voted against the Maastricht Treaty in parliament, in defiance of the then Conservative leader and Prime Minister John Major.

Madam, these are the teeth of a killer
This man must have meat or die

Lord Tebbit on Iain Duncan Smith

This principled stand ruled him out for promotion from the backbenches under Mr Major.

More recently it is reputed that Mr Duncan Smith once threatened to resign from the shadow cabinet along with colleague David Heathcoat-Amory if William Hague refused to rule out joining the single currency for a decade.

Ties with Tebbit

Mr Duncan Smith's parliamentary career took off in the 1992 general election as he held Norman Tebbit's old seat of Chingford.

There are many similarities in the two men's politics, if not in their tone - Mr Duncan Smith being some what softer spoken than the former party chairman.

Duncan Smith is close to the former PM

One tale from 1992 has the pair out canvassing in Chingford. A woman stopped the would-be MP to ask his opinion on fox hunting - before he could answer Lord Tebbit had intervened saying: "Madam, these are the teeth of a killer. This man must have meat or die."

An active Christian, Mr Duncan Smith joined the Tory party in 1981, after being profoundly affected by Lady Thatcher's election victory in 1979.

He is said to be close to the former prime minister, who was reported to be an unofficial backer of his campaign.

Lady Thatcher is believed to have been behind a propaganda coup which saw Mr Duncan Smith hold a meeting with George W Bush's defence secretary, Donald Rumsfeld, before his UK opposite number Geoff Hoon had a chance to brief him on EU proposals for a rapid reaction force.

It goes without saying that Mr Duncan Smith is fiercely opposed to any moves towards a potential European army and that he believes the UK should back American plans for a National Missile Defence system.

Redwood backer

In the 1997 battle for the Tory leadership Mr Duncan Smith not only rejected William Hague to back leading Eurosceptic John Redwood, he ran his campaign.

Only after Mr Redwood was knocked out of the contest did Mr Duncan Smith swing behind the eventual winner.

Mr Duncan Smith supported John Redwood for the Tory leadership

As social security spokesman he led Tory opposition to major planks of the government's programme such as welfare to work.

Michael Portillo launched his campaign for the leadership with a plea for inclusiveness in the party, and Mr Duncan Smith did likewise.

His instincts are generally seen as socially conservative: for capital punishment, against gays in the military and against women fighting on the front line.

But during the campaign he has advocated tolerance of "different adult lifestyles" and is reported to have privately hinted he is flexible on section 28, which prevents councils "promoting" homosexuality in schools.

Some observers view such "liberal" signals as an attempt by Mr Duncan Smith to appeal beyond his core vote.

Mr Duncan Smith is married with four children; his wife Elizabeth is a secretary.

Key campaign dates

20 August: Ballot papers sent out

22 August - 7 September

11 September: Deadline for return of ballots

12 September: New leader announced

His father was a World War II pilot before he went into business; his mother was a ballet dancer.

Mr Duncan Smith's beliefs make him a natural political heir to the Thatcher legacy.

But his vision for Britain's future may be perceived as too right wing for him to appeal to enough of the general public to take the Tories back to Downing Street.

In any case Mr Duncan Smith still faces one more hurdle before he can take over the mantle from Mr Hague - a ballot of the Tory rank and file to decide between him and Mr Clarke.