Both formidable leading ladies have taken up the cudgel (I hesitate to use the word battleaxe) in the cause of greater sporting equality on the playing field and in the boardroom.
Not enough women, they argue, are in sport's corridors of power.
Now that may sound curious coming from two women who are actually in perfect positions of political power as far as sport is concerned.
Miller is actually Britain's Games Mistress with a portfolio in her Governmental department which embraces sport - as does that of Harman in hers. They are the governesses respectively of Britain's Minister for Sport Hugh Robertson and the Shadow spokesman Clive Efford.
So methinks they may protest a tad too much, especially as the chief executives of both Government quangos, UK Sport and Sport England, the bodies responsible for dishing out the cash that keeps British sport flowing and glowing, are also female - Liz Nicholl land Jennie Price.
And until recently UK Sport had a female chair, Baroness Sue Campbell - still chair of the Youth Sport Trust - while Sport England might have had one too in Baroness Tanni Grey-Thompson had not Miller, allegedly such a champion of women's rights, played petty politics and put the block on her appointment.
Yet Miller, who understandably, like Harman, boycotted The Open golf championship at Muirfield because the club's ban on women members, says:" "I want to see much better female representation in sports administration.
"Governing bodies that are funded by the taxpayer are expected to have boards that are 25 per cent women by 2017 or put their funding at risk."
Ardent feminist Harman not only stridently concurs but has pitched in by writing to Christian Prudomme, director of the Tour de France to propose a women's Tour event to be held alongside next year's Grand Depart which takes place in Yorkshire, only to be told to get on her bicyclette.
At the risk of being labelled a male chauvinist - which ladies I assure you I am most definitely not - I do believe that sport is more inclusive than it has ever been and that the profile of women's sport has never been higher, nationally and internationally.
Of course there are pockets of resistance like the intransigent men of Muirfield and other all-male golfing preserves (though there numerous all-women clubs too); our own Football Association, where the admirable Heather Rabatts is a lone voice for both women and ethnic minorities; and FIFA, where President Sepp Blatter seems only interested in women if they are wearing suspenders (he was once head of the society for the preservation of that garment).
Elsewhere the barriers are coming down fast, notably in the media. The newspaper for which I write, the Independent on Sunday, has become the first national publication to pledge to increase its coverage and raise awareness of women's sport.
The paper has called for greater efforts to ensure school sport appeals to girls, better publicity and broadcast coverage for sportswomen, better pay for female athletes, more corporate investment and sponsorship and women on the boards of all national governing bodies.
It is surely coincidence that the IoS has a new editor - who happens to be a woman. Interestingly, one of its rivals, the Mail on Sunday, has just appointed the national newspaper industry's first female sports editor.
And there is certainly no, lack of female presence writing on the sports pages of most papers now, while our TV screens sometimes seem dominated by female sportscasters, presenters and interviewers.
Sky Sports is veritable catwalk of feminine pulchritude, invariably blonde. Managing director Barney Francis tells me he receives at least a dozen applications a day from wannabe presenters, nearly all of them women.
Oh, and by the way, the head of BBC Sport is a woman - the ex-gymnast Barbara Slater. And now we learn that Charlotte Green is to be the first female reader of Radio 5 Live's classified football results, succeeding the venerable James Alexander Gordon.
On the box names polished performers like Clare Balding, Gabby Logan and Sue Barker are as professional and knowledgeable as any male counterpart. And why shouldn't they be?
London 2012 was something if a watershed for women's sport, with more women than ever representing Team GB. In a total of 542 British athletes 262 - 48 per cent of the team - were women.
Then first medal for Team GB at London was a woman - road cyclist Lizzie Armitstead and the first gold was from women rowers Heather Stanning and Helen Glover. Also London was the first time women were able to compete in all sports, with the debut women's boxing.
Overall 2012 saw record participation from women, who made up approximately 44 per cent of Games competitors. With the inclusion of female athletes in National Olympic Committee (NOC) delegations from Saudi Arabia, Qatar and Brunei Darussalam, all NOCs had sent women to the Games by 2012 and women athletes outnumbered men on 35 NOC delegations, from some of the smallest teams to the largest.
Indeed, think 2012 and you think women. I asked my 11-year-old grandson the half dozen British personalities he remembered best from the Games. After Mo Farah the next five were all women...Jessica Ennis, Nicola Adams, Laura Trott, Gemma Gibbons and Sarah Storey.
Whisper it softly, but the glass ceiling does appear to be cracking, if not shattering, even in the predominantly old boys' club that is the International Olympic Committee, where three of the 15-person Executive Board are now women.
Not enough, but at least they are influential. The wonderfully accomplished Nawal El Moutawakel of Morocco is one of four vice-presidents, German Claudia Bokel heads the Athletes' Commission and Sweden's Gunilla Lindberg is chair of the Coordination Commission overseeing the 2018 Winter Games in Pyeongchang.
Shame that none of the six candidates in the upcoming Presidential election are women because El Moutawakel in particular, who had considered standing, may well have given the chaps a run for their money.
Last week insidethegames reported a significant international breakthrough in hitherto African male domains - Isha Johansen becoming President of the Sierra Leone Football Association thus joining Lydia Nsekera of the Burundi Football Federation as the only two female presidents' of national football associations in the world.
And Yulia Anikeeva, acting-President of the Russian Basketball Federation since June, has been voted into the position full-time.
On the debit side back home the Independent reports that British Cycling is one of five national sporting governing bodies without a single woman on its board. Of the 46 national governing bodies (NGBs) that receive money from Sport England, British Cycling, British Taekwondo, the British Wrestling Association, Goalball UK and GB Wheelchair Rugby still have all-male boards.
In many governing bodies, there are women on the board, but a tiny proportion in leadership positions. The British Judo Association, for example, has two women on its board, but only four per cent of all leadership roles are taken by women.
Despite the stellar performance of so many female competitors in the Games, senior sporting figures say the bodies that govern their sports are failing to give women a strong enough voice.
Leora Hanser, director of campaigns at the Women's Sport and Fitness Foundation (WSFF), said: "It is really disappointing that after the Olympics last year, WSFF's research found that six sports governing bodies still don't have a single woman on their board. A lack of diversity means that they are missing out on areas including participation, investment and media profile."
The former England cricketer Rachael Heyhoe Flint, who is one of two women on the Board of the England and Wales Cricket Board, said: "I can't see any reason not to have a woman provided they merit a place. If Boards said, 'We won't have anyone of a certain ethnicity or nationality' that would be illegal."
While former Paralympian icon Baroness Thompson adds: "I struggle to understand why some governing bodies are holding out. They're missing out on a massive opportunity. I'm tired of hearing things like 'there's not enough good women in sport'. We all know that's nonsense."
This is true, but let's be honest, there is a major problem with some women's sport which has little public appeal, particularly team sports. How many really want to watch it?
Surveys suggest that even many women don't. A women's football international would never fill Wembley, however much it was publicised though we in the media must shamefully admit that even if England won the women's World Cup it would still be recorded downpage to a Wayne Rooney groin strain.
There is another obstacle to be overcome, too. According the WSSF most girls think getting sweaty isn't feminine. "We're facing a health crisis and with young girls aspiring to be thin instead of fit, it ls only going to get worse," they say.
But actually, in so many other ways, things are getting very much better, albeit slowly.
Thankfully women are no longer sporting suffragettes because, in the immortal words from the days of that great emancipator Billie-Jean King and women's lob, you've come a long way, baby.
Yes, there's stiil a way to go, but perhaps not quite as far as our two Girls On Top, Mrs Miller and Ms Harman, seem to think.
Alan Hubbard is a sports columnist for The Independent on Sunday, and a former sports editor of The Observer. He has covered a total of 16 Summer and Winter Games, 10 Commonwealth Games, several football World Cups and world title fights from Atlanta to Zaire