Theresa May’s first speech on the steps of No 10 a year ago, in which she pledged to tackle the “burning injustices” of modern Britain, put a bold and unexpected emphasis on social wellbeing in the first moments of her government.

The newly minted prime minister identified the neglected “Jams” (just about managing) families, “ordinary working class” households who were doing their best but struggled with job insecurity, mortgage repayments, and the ever-rising cost of living.

“The government I lead,” May promised the Jam families, “will be driven not by the interests of the privileged few, but by yours”.

May this week plans to return to the wider theme in a speech billed to repair her damaged authority as leader. In the 12 months between the two speeches, her position on Downing Street’s steps has been badly dented.

She will say her commitment to social justice and determination to address difficult issues remains “undimmed”, despite her calamitous general election performance. But pre-briefings suggest it will be light on specifics (unlike last year, where it sprinkled with references from poor access to mental health services to unequal life expectancy).

Of the legendary Jam families, there appears to be no mention.

For their part, the Jams might be forgiven for believing that May has objectively failed to deliver much at all to them over the past 12 months. For many, the household economic outlook remains grindingly flat: static or falling wages, painful gas and electricity bills (though May has promised to reform the energy market), eye-watering rents (for many younger Jams home owning is a distant pipe dream) and rising food prices fuelled by post-Brexit inflation.

Employment may be at a record high, but the Jams know secure jobs are harder to come by. Work is the best route out of poverty, May insists , but Jam families also know that irregular or zero hours jobs are often no barrier against destitution and food banks. A record 60% of British people in poverty now live in households where someone is in work. Keeping the Jam family finances in good condition increasingly requires the salaries of two working parents, and yet for many the Tory promise of good quality, affordable childcare remains out of reach.

May has shown no interest in reversing cuts to universal credit work allowances made by former chancellor George Osborne (to the tune of £4bn a year by 2021), and yet these will result in some working families losing up to £2,800 a year – the same Jam households she wanted to help.

Similarly she has kept her predecessor’s freeze on working-age benefit levels. The combination of rising rents and shrinking housing allowance rates will leave Jam households potentially needing to find hundreds of pounds each month to avoid eviction, according to Shelter.

While the level of the government’s “national minimum wage” has risen from £7.20 to £7.50, this gain has been offset by the freeze in tax credits and reduced housing benefits, according to the Joseph Rowntree Foundation. Over the past year families on tight budgets have fallen further behind what the public considers to be a decent standard of living.

There were also the discordant signals to Jam families from May’s election manifesto. Having told them she understood their fear of the missed mortgage payment, she threatened to take away their home to pay for social care through the “dementia tax”. Her plans to abolish universal free school meals for younger primary school children left a working family with two younger children needing to find £900 a year for dinner money. The policy has not survived the election.

Ironically, May’s audacious grab last July for the working class vote was until a few weeks before the election result widely regarded as a triumph. As it turned out, the younger Jam families surged behind Labour’s less complicated offer of support for struggling strivers. Either they did not believe May and the Tories had any real intention of delivering financial respite for ordinary working families, or they doubted their competence to do so.