It slipped out quietly this month in the brouhaha of the approaching budget. The regulations listing acceptable ID documents that will allow people to vote at elections were not included in the shameless voter-suppression bill that passed through parliament this year. Are you surprised that the list includes all kinds of acceptable ID held by older voters, but that ID the young might have has been struck out? The whole purpose is to make it harder for young people, poor people and those who often move home to vote.

So many outrageous things have happened recently that indignation fatigue is a risk. We grow weary, blase and cynical. But warping the voting system in the right’s favour is a permanent harm, copied from the US. First-past-the-post already gives the right a huge electoral advantage, but the Tories want more.

As from next May’s local elections, all voters must bring along ID specified in this list. As the Electoral Reform Society (ERS) says, the kind of photo ID required is what older people are more likely to have. For example, why is a Transport for London Oyster card for 60+ travellers acceptable, but not a near-identical Oyster 18+ card? Let that stand as their true intention. Voters who don’t have a driving licence or passport or various forms of disabled person’s ID – all of which are more likely to be held by the old – can apply to their local authority for a free plastic voter ID photo card. How many would do that?

This barrier will, research by the Joseph Rowntree Foundation shows, disenfranchise many low-income voters. Getting one of these special voter IDs is harder for those who work irregular hours, or who may not speak good English or know how to use the technology. The government was plainly thinking of exactly those people in setting up barriers to stop them voting.

The Lords voted by a big majority to add in all kinds of easier ID, such as bank statements, bills, student ID, library cards and much more. But their amendment was struck out in the Commons. The pretence that there is a serious electoral fraud problem was debunked by evidence from the 2017 election: there was just one – yes, only one – conviction for voter impersonation at a polling station. Postal voting has seen more cases. The cost of imposing the new ID – extra staff at polling stations and councils issuing it – will be up to £180m a decade, according to the Cabinet Office. Turning people away, and telling them to return with other ID, will cause trouble. In the few trials in England in 2018 and 2019, of 3,000 people turned away, more than a third never came back.

This voter suppression comes on top of David Cameron’s previous assault on young voters. He barred colleges from block-registering all their students to vote. The serious problem is that the young are 40% less likely to vote; Bobby Duffy, director of the King’s College Policy Institute, finds them 40% less likely to think it a civic duty. Maybe they resist the meagre choices on offer. But David Willetts, a dedicated campaigner in the Lords against voter ID, says the Resolution Foundation, whose advisory council he chairs, finds the greatest obstacle to the young voting is living in private rented accommodation, where only 63% are registered to vote owing to moving frequently. He would force landlords to register their tenants.

Here’s why the government wants to keep the young away: voters over 70 are three times more likely to vote Tory than the 18-24s. Every year of life we age, we grow 0.35% more likely to be Tory. That may not sound a lot, “but it’s very valuable over a lifetime”, says Duffy. The tipping point for turning Tory has generally been growing older at each election: it was age 47 in 2017. No wonder the Tories worry they are dying out. Brexit saw a deep divide, with only 28% of millennials voting leave, compared with 61% of oldest voters.

This is what the young need to know: if you don’t vote, you don’t get. The old, with their pension triple lock, pension tax relief, no national insurance, untaxed property wealth and freedom passes, are rewarded, while, since 2010, government spending swivelled away from children, families and the young. Youth centres, Sure Starts, Connexions careers services, and children and adolescent mental health services are disappearing.

With this government, expect utter incompetence. Lord Willetts points out the irony that many turned away from voting will be “older, Brexit, Tory voters” without photo ID. “Most people have no idea they will have to bring photo ID to vote,” he says. He warns that, in seats won by a tiny margin, the number turned away from polling stations could be greater than the majority.

Meanwhile, Labour has backed votes at 16 for years. I would make voting compulsory for first-timers, so they get the habit. What’s needed now is an army of Greta Thunbergs to get all over-18s out to vote on green and social justice issues. Be warned, for the first time in history the latest census shows there are more over-65s than under-15s. There is no indignation deficit among the young: they’ve just got to get out and vote.

• Polly Toynbee is a Guardian columnist