SIR - The Conservative Party is fortunate at this leadership election to be able to choose between two strong personalities who offer two distinct visions. Ken Clarke has many qualities. But I have no doubt that Iain Duncan Smith would make infinitely the better leader.
Indeed, I simply do not understand how Ken could lead today's Conservative Party to anything other than disaster. He is at odds with the majority of its members on too many issues. He appears to be an even keener enthusiast for the euro than is the Prime MinisterTony Blair, let alone the ChancellorGordon Brown.
He seems to view with blithe unconcern the erosion of Britain's sovereignty in Europe. And in the strategic choice of whether Britain aligns herself with an emerging European super-state or whether our relationship with America should remain paramount, Ken would, as is clear from his remarks, be on the side of Brussels.
Ken Clarke's supporters pretend that none of this matters. But it does and it will. Time and again, Europe will be at the forefront of politics. Time and again, the Conservatives would be exposed as either hopelessly split or deeply cynical - either openly rebelling against their leader or going along with policies which they knew - and which others knew they knew - to be wrong.
On such questions, Iain Duncan Smith holds a principled position and he has fought for it with energy and honour. When he is criticised for lacking ministerial experience, it should be remembered that he does so only because he put his integrity before his ambition.
Oscar Wilde once wrote that "experience is the name everyone gives to their mistakes". It would have been reassuring to hear from Ken Clarke about some of the mistakes which in 1997 led the Conservative Party to the greatest defeat in its history. After all, he - not Iain Duncan Smith - was one of those who made them.
True, that is the past. But it is a past in which Ken, with his old-fashioned views of the role of the state and his unbounded enthusiasm for European integration, remains locked. Such views have done their damage and they have had their day.
By contrast, Iain Duncan Smith is a fitting spokesman for a new generation of Tories. He offers a fresh and invigorating future for the Conservative Party and for Britain. He knows that the party will never regain its standing by aping or outflanking Labour.
He understands that the task of the Conservative leader is to hold on to one's core support while reaching out to those who are Conservative by instinct but not yet by allegiance. He grasps that the way back to government lies upon the common ground, the shared values of the British people.
I am confident that, if elected leader, Iain will restore the Conservative Party's faith and fortunes. He deserves support.
Lady Thatcher
London SW1