In the 1960s the unassuming Mary Wilson was told by Downing Street officials that she could not receive £33 for a poem published in a magazine as it could be seen as her trading on her husband’s position as prime minister. What a difference 40 years has made to political values.

Last week Cherie Blair earned a nifty £30,000 for her 90-minute appearance at the Kennedy Center in Washington where, before a corporate-sponsored audience, she answered questions about juggling family and legal career and the job of being married to the prime minister.

“It’s a terrible sort of tightrope one is walking all the time,” she said.

Billed as the “trailblazing first lady of Downing Street”, introduced by her friend Hillary Clinton as “an extraordinary intellect, as well as a profoundly kind and caring person”, and with Sir David Manning, the British ambassador, as her warm-up act, finally she was being feted as the celebrity she feels she has become.

What’s more, they seem to like her in America. That night, to warm applause, she was Superwoman, the very persona that she denied being when, with a wobbly voice and moist eye, she apologised for her involvement with the conman Peter Foster in one of her intermittent scrapes — which seem always to involve money, especially efforts to save it.

In May last year a senior Downing Street adviser talked about Cherie having “lost her way”, feeling she was presidentially above the humdrum protocols of Westminster life. A year on, insiders say she has almost no restraint and feels entitled to do these things to earn money. One puts it down to “greed, arrogance and an inflated sense of her worth”. She is reported to be refusing to stop making paid speeches.

Cherie has always had great expectations. As a young woman she was clever, diligent, never wildly aspirational or even financially motivated, but principled. When she came top of her bar exams she had the pick of chambers and legal specialisations, but instead of opting for “big money bar” in commerce she went for human rights, legal aid, family law; the poor cousins of the profession but perfect for a firebrand idealist. She married, however, a bright young commercial lawyer who would have made their fortune had he remained at the bar instead of reinventing the Labour party.

When the couple first met she was living in the Hackney house of her friend Maggie Rae, a solicitor — her entrée to both active politics and the world of soon-to-be rich young north London lawyers with lefty leanings and Georgian houses. Most of them were from privileged homes very different to her own working-class background.

In Labour circles of the 1970s her authentic Merseyside origins gave Cherie a special cachet, making her twice as exotic to the Fettes/Oxford-educated Blair. Over the decades, however, it has also led to her feeling that she has the right, almost the obligation, to use whatever opportunities to make money that come her way. (She will never inherit any like many of their friends, after all.) The problem here is that she did not “earn” her Washington fee last week in the way she earns her legal fees, with expertise and cleverness. She traded on her married name, which is hardly less distasteful than piggybacking on the rich, powerful parents she never had.

In the past she has lectured on law as Cherie Booth QC and been paid handsomely, and nobody — quite rightly — has commented; but even her supporters find the first lady fees unacceptable.

“It’s indefensible, absolutely wrong,” says one old friend and confidant. “I just have no idea why she’s doing it.”

Cherie seems to relish the warm glow of public service and good works but not the curtailment of wealth creation that goes with it. She is vocal in her opposition to Guantanamo Bay and her sympathy for Palestinian suicide bombers, but her politics seems dissociated from her personal priorities. She is a creature of scrupulous morals but her money-making doesn’t help raise standards in public life. Nor did the intimate insights into the Blairs’ sex life she offered The Sun in a joint interview before the election — Question to prime minister: Are you up to it? Cherie: He always is! It can seem as if the intensely private, devoutly Catholic Cherie, so elegantly solemn in her mantilla at the papal funeral, periodically mislays her sense of propriety and her old moral compass. For one concerned with the problems of the have-nots she seems not to grasp how badly stories of her money-spinning play.

It is unheard of to feel sorry for the spin doctors of Downing Street, but last week they were stumped, lost for answers to Cherie’s behaviour as they never were over WMD or tuition fees.