“Politics must have a noble purpose.” Many Britons will have choked over their tea and marmalade to hear these words from a former chairman of the Conservative Party, Maurice Saatchi, in an extraordinary interview for the BBC.

You don’t need to be as cynical as most people in this country are about politicians to imagine the reaction. Did Lord Saatchi mean by “noble purpose” his own elevation to the House of Lords, the usual reward for loyal service? And who is he, one of the most celebrated names in advertising, to agonize in public about how he failed to overturn “the fiction of the focus groups?” Will voters take kindly to being told by a plutocratic peer that the Tories’ great mistake was not promising to lift the burden of income tax from the poor? And what on earth did he mean by advising those choosing the next Conservative leader to “look into the eyes” of every candidate?

Yet the fact is that Lord Saatchi is so obviously sincere, so effortlessly charming, and so overwhelmingly right that the Tory party will have to sit up and take notice. As one of the few leading Conservatives who has been highly successful outside politics, he commands respect in a party whose leaders have recently enjoyed an average tenure of 18 months.

Lord Saatchi and his brother Charles were the children of Iraqi Jewish refugees from the Baathist regime. During the 1980s, they built up the largest advertising empire in the world, Saatchi & Saatchi, then abruptly sold up. Charles went on to become the most powerful figure in contemporary art, but Maurice changed his mind, rebuilt the firm and, having made his name as Margaret Thatcher’s ad-man, decided to go into politics on his own account.

After years on the fringes of power, he was appointed co-chairman of the party when Michael Howard became leader in November 2003. Lord Saatchi immediately began propagating his message that Conservatives must replace their selfish image with a compassionate one. He wanted them to make a moral case for promising to cut taxes from European levels of nearly 50% to American levels of around 30% of GDP.

Lord Saatchi recognized the strength of Prime Minister Blair’s appeal, offering social justice financed by a stable, fast-growing economy. But he believed that Mr. Blair had become a liability to the Labor Party and that the Tories could win.

He now admits that he was wrong about Mr. Blair’s unpopularity, but, in any case, his advice to aim for the moral high-ground was ignored by the man who appointed him. Michael Howard ran a narrowly focused campaign designed to frighten voters with mass immigration. He also promised cleaner hospitals. The Tories behaved as though they dared not mention the economy, according to Lord Saatchi, and their only way of demonstrating that they cared about the poor was to pick fights with right-wing tax-cutters in their own ranks.

Lord Saatchi, to his credit, does not duck his own responsibility for the Tories’ third successive defeat. He has a dry wit, poking fun at the dreary line-up of Tory leadership contenders (28 at the last count) with the suggestion that “it would be marvelous to have Brad Pitt as leader of the Conservative Party.”

But the underlying tone is elegiac, almost despairing. Unless the next Tory leader finds a convincing answer to Mr. Blair’s question (“Why do we need the Conservatives?”), he or she may be the last. Lord Saatchi writes his own political epitaph: “I did not convince the party that if you don’t stand for something, you will fall for anything.”

Why should anyone in America care about the views of Lord Saatchi? Or, for that matter, about the future of the British Tories? Two good questions, you may feel, but the answer to both was given last weekend, when the Brussels summit made it clear that Europe has no idea what to do next. For all their hypocrisy, mediocrity, and inconsistency, the British Conservatives are the only major party in the European Union that has mounted a serious critique of the E.U. over the past decade. It is important for this critique to be heard loud and clear now that the project of a European constitution is dead in the water.

Lord Saatchi has put his finger on what the Tories need to do in order to be heard again. Conservatives do indeed need a “noble purpose”; they cannot afford to leave idealism to the left. President Bush gave Americans such a purpose after September 11, 2001, and Mr. Blair has tried to do the same.

Even if the Tories had a leader with Mr. Pitt’s looks and Mr. Saatchi’s brains, they too would need a noble purpose. Once they repudiate their equivocations over Iraq and Europe, stop pulling their punches on the economy, and explain how they will give families back their independence from the state, the world just might start listening to them again.