The first ever Global Disability Summit took place in London last week, with more than 700 delegates from governments, charities and disability organisations around the world.

In a speech last year to herald the event, Penny Mordaunt – the international development secretary and former minister for disabled people – said the summit would showcase Britain’s “commitment to transform the lives of people living with disabilities”. Theresa May was similarly enthusiastic, pledging the summit would be dedicated to “transforming the lives” of disabled people, and showing how “committed” Britain is to ending disability discrimination.

I can’t help but be reminded of a scene in The Handmaid’s Tale in which the rulers of Gilead put on a grand show to impress visiting international delegates; with the bruised handmaids kept hidden, they are free to present their nation’s treatment of women as something to aspire to.

I wasn’t the only one who found this situation jarring. Disabled campaigners, supported by international guests, held a counter-event outside the summit in a bid to highlight to visiting delegates the British government’s track record on disability rights.

For a country that has been found guilty by the United Nations of “grave and systematic violations” against its own disabled citizens to cast itself as a role model is, at best, out of touch and at worst hypocritical. It’s also manipulative: the Conservatives repeatedly spin their own disability rights record and express concern about the treatment of disabled people in developing nations to distract from their own dodgy record. When defending itself from the UN’s damning report last year, Mordaunt cast Britain as a support for troubled nations, even claiming the Conservative government’s own treatment of its disabled citizens could be a “catalyst for change elsewhere in the world”.

Of course, other countries fail to uphold the rights of disabled people, sometimes to a horrifying degree. As a disabled person born in Britain, I’ve always been aware that I’m relatively lucky: I was able to be raised by my parents, go to school, and get a job. In many other countries I would not be writing this column. From Ukraine to Mexico, disabled children can be kept in orphanages, autistic infants locked in cages, and children with cerebral palsy tied to rough metal frames to “teach them how to stand”. In Ghana, some disabled people – seen as cursed by evil spirits – are exiled from villages, and even murdered.

Such abhorrent practices are not confined to poorer countries, either. Developed nations such as Japan and Australia have a recent (and current) history of forced sterilisation of disabled women, which falls under the UN definition of torture.

But that things are worse elsewhere is hardly a justification for ill-treatment here. That a Parkinson’s patient in Manchester is at a relative advantage compared with a disabled person in Ghana will be little comfort when he’s queueing at a food bank in one of the richest nations on earth.

Nor are other countries’ shortcomings an excuse not to acknowledge our own. Multiple independent bodies have criticised our progress on disability equality in recent years. In 2017 an inquiry by the United Nations concluded that Britain was failing to uphold disabled people’s rights across a range of areas such as education, work, housing, health, transport and social security. Meanwhile, the Equality and Human Rights Commission has said Britain’s failure to implement disability rights as society’s is a “badge of shame”, with anything from exclusion by private landlords to inaccessible sports stadiums amounting to disabled people being treated as “second-class citizens”.

Such inequality is not the responsibility of any single government; it’s a long-term problem in Britain’s social and economic structures. But contrary to the rosy image the government portrayed last week, the Conservatives’ austerity measures, which disproportionately affect disabled people, have actively pushed disability rights in this country back decades. The mass testing of disabled people for personal independence payments is taking away their social security, leaving them housebound and cut off from their communities. Many have died after being forced to look for work.

Social care cuts are forcing wheelchair users into care homes against their will or left to sleep in their own urine because there’s no one to help them stay clean. Poverty, which is already significantly more likely to affect someone with a disability, is deepening; it’s now commonplace for disabled people to skip meals in the UK or even to be so destitute they can’t afford deodorant.

The idea of a Global Disability Summit is an admirable one. As a wealthy nation, not to mention one with a colonial past, we have a responsibility to assist other nations and their disabled citizens, while a global approach can help us all learn from one another. But some self-awareness and, frankly, honesty about our own track record wouldn’t go amiss. Spare us the posturing on the global stage. If this government really wants disabled people to be treated as equals, they can start with looking closer to home.

• Frances Ryan is a Guardian columnist