Frances O'Grady could be very dangerous for David Cameron. She is that elusive thing in the political jungle – a reasonable union leader with a common touch, who even gets glowing write-ups in right-wing newspapers. About to be anointed as general secretary of the TUC, the 52-year-old single mother of two talks like a normal person, balks at macho stand-offs between politicians and union barons, but comes armed with a neat line in withering put-downs.
And she is, as you can see from the photograph on this page, a woman. If the Prime Minister does have a "problem with women", it is only going to be exacerbated by O'Grady speaking for 6.5 million union members.
"I worry that some politicians still think we are living in the 1950s where the man is the main breadwinner and the woman works for pin money. Actually, most families where there are two parents depend on two incomes to get by. It really sticks in the throat of a lot of women, the idea that they're easier to pick on and their money is somehow less important."
The sidelining of women in the cabinet reshuffle, and the rumours of female ministers being sacked by the PM as he drank wine and remarked on their age, have not helped. "It's bad politics, isn't it? Everybody agrees [the reshuffle] is a shift to the right as well as a shift to the men."
Cameron's swipe at Ed Miliband last week was the latest in a "series" which "are going down very badly" with female voters. "Even down to that off-the-cuff comment [to Miliband] about 'butch up'. I was thinking actually they need to 'fem up'. That's the real challenge for any party that wants to win women's votes."
Is the Prime Minister basically sexist? She laughs, hard. "I wouldn't claim to know him well enough to say…" is her initial response. "What I do know is that we are seeing very large numbers of women workers in the public sector being sacked … having pay squeezed, living standards under attack. Women are feeling particularly hard done by. There is a problem for the Government on that front."
A woman taking over the TUC is seen as a big deal − it is the first time in its 144-year history − but she is relaxed about the trappings of the new office just up the corridor. However, the Arsenal fan will be pleased to see the back of the bright blue carpet chosen by her predecessor, Brendan Barber, an Everton fan.
She hopes to use her role at the head of the TUC to "nail some myths" about the trade union movement being male-dominated. "Three in 10 of our union leaders are women, 50 per cent of our membership is women, this is a different trade-union movement to the one a generation ago."
The imminent battle is over George Osborne's plan for local pay rates for public-sector workers. Announced in the Budget, it has since been denounced by unions, Liberal Democrats and a growing number of Tory MPs who warn that varying pay for teachers and nurses is unfair and will take millions out of local economies. Supporters say it would save £6bn a year and stop public-sector pay outstripping the private sector in poorer areas. More details are expected this autumn.
"This is a shambles and it's hugely unpopular," O'Grady says. "It's unfair, it's unworkable and it's bad for the economy. Why should a teacher working in some tough inner-city school in Newcastle be paid less than a teacher working in a leafy suburb in Surrey?
"It does worry me that sometimes politicians − who may never have had responsibility for running an organisation − are dabbling in these sorts of unwise initiatives. Everybody else will be left with the mess and have to clear it up." She also believes it could lead to a "widening of the gender pay gap".
It is quite an achievement to get Tory MPs supporting a TUC campaign. O'Grady has also been working with the Women's Institute, another unlikely bedfellow, on travel safety. "We are very persuasive," she says, with another laugh. She laughs a lot, sometimes nervously, often at the absurdity of the politicians she has to deal with.
Fresh from the summer holidays, the Government launched a blizzard of announcements, most notably on reforming – again – the planning system. "If those one million young people currently on the dole could be employed to fix everybody's conservatories, that's the problem solved? It's not quite that simple."
The TUC is not affiliated to the Labour Party, but O'Grady concedes that they have "shared values" which have enjoyed a "renewal" under Ed Miliband. However, she also holds out an olive branch to the Liberal Democrats, whom she believes had little choice but to join the Tories in coalition. Notably, she has "good relationships" with Vince Cable, who has been feted by the Labour leadership as someone they could do business with in the event of a Lib-Lab coalition. O'Grady worked with the Business Secretary and the Unite union to secure 2,100 jobs and create 700 more at Vauxhall's car plant at Ellesmere Port.
Next week Cable will launch his long-awaited industrial strategy, though it is not clear how much of it will be held back by his coalition partners. "The difficulty for the Government is there's this ideological straitjacket of the market will provide, let the market rip and everything will work out…. It's back to trickle-down economics, which, it's plain to see, have not delivered."
Just a fifth of the cuts have hit so far. Len McCluskey, general secretary of Unite, boasts that there is a "real likelihood" of more strikes before the end of the year. O'Grady is more measured: "It depends whether our members vote for it. That's the bottom line."
The TUC returns to the seaside today for its annual congress in Brighton, just as O'Grady's son prepares to celebrate his 21st birthday. O'Grady's first job was washing up in an Oxford college kitchen, a few years before a young David Cameron joined the Bullingdon Club in charging around the city. A union official for almost her entire adult life, she admits she was not a "poverty-stricken parent", and says she brought up her son and daughter on her own, "with a bit of help from good friends". But she believes it gives her an insight into real life that many in the Westminster village lack.
She recalls listening to a politician on the radio lambasting single parents. "I remember my daughter turning to me – she was about eight – and saying: 'They're talking about us.' It was the look on her face…
"I do know what it's like to worry about bills, I do know what it's like to worry about even finding a child-minder, never mind paying them. If you start from the position that most people are trying to do the best they can, and that the role of government is to help them, that's very different to seeing large numbers of [single] parents as intrinsically a problem."
One of the upsides of her children growing up is that she no longer has to endure trips to the cinema to watch the latest blockbuster or Disney release. "I like independent films... European films. I do go and see popular films as well because my kids force me. If it was my choice, I'd be down the Renoir." She also draws, portraits mainly. "Drawing is easier. I'd paint if I had time."
Becoming the most powerful voice in the union movement – and explaining to the Prime Minister the error of his ways – will mean even less free time. The watercolours will have to wait.
1959 Born in Oxford to Margaret and James, a British Leyland shop steward at the Cowley plant.
1971 Attends Milham Ford Grammar, which becomes a comprehensive.
1976 Washing dishes at an Oxford college motivates her to challenge the lifestyle of privileged undergraduates. Went on to read politics and modern history at Manchester University and then industrial relations and trade union studies at Middlesex Polytechnic.
1982 Joins TGWU, her father's union. Has two children, a daughter and son, who she raises as a single mother after splitting with her partner.
1989 Co-writes Women, Work and Maternity: the inside story.
1994 Joins TUC as a campaigns officer.
1997 Appointed to lead the New Unionism campaign. Founds academy training union organisers to challenge "male, pale and stale" stereotype.
2003 Becomes TUC deputy general secretary.
2012 Is elected TUC general secretary.