While the country is preoccupied by the start of the two-year Brexit process, there are more immediate challenges for British young people. Beginning today, government regulations will deny thousands of 18- to 21-year-olds any help with their housing costs through housing benefit. For students of the future, this will be a textbook case study of policy and political misjudgment. A triumph of dogmatic ideology over facts, a refusal to allow proper scrutiny of the decision being taken and an arrogant dismissal of concern about the consequences.

The savings from this cut are little more than a rounding error in the Department for Work and Pensions’ budget – amounting to just 0.01% of overall spending next year. But while the savings are small, the costs are potentially huge. The charities who work with young people in housing difficulty, day in and day out, have been clear about the hardship this crude cut will cause. Centrepoint estimates that about 9,000 young people will be put at risk of homelessness. Shelter has said: “There is no way this isn’t going to lead to an increase in rough sleeping.” The charity Crisis – which played a big part in delivering the new cross-party homelessness reduction bill – says this “runs entirely counter” to the aims of that bill, and “could spell disaster for the many vulnerable young people rightly entitled to help”.

Since 2010, the number of people sleeping rough on our streets has more than doubled, and the number of households accepted by local councils as homeless has risen by almost a half. By some estimates, the total number of homeless people in England has now hit a quarter of a million, more than 100,000 of them children. The removal of support for young people’s housing costs is a policy that is guaranteed to drive homelessness levels still higher. The consequences of this policy could not be clearer.

Ministers know they can’t justify this change. This is a hangover from the Cameron-Osborne era of political posturing on benefits. When I dragged the government minister responsible to House of Commons recently, she admitted no full impact assessment had even been done, and refused to release the narrow appraisal government officials had carried out on the equalities effect of this cut. A policy which could make so many young people homeless needs proper scrutiny, not a political cover-up. They deserve better from ministers than this high-handed approach.

When homeless charities are speaking out, but ministers refuse to listen, people will rightly ask – what is the government hiding? And why is a prime minister who claims she wants a “country that works for everyone” putting thousands of young people at risk?

Quite apart from the problems it will cause, there is a deeper principled objection. Young people affected by this are old enough to marry, work, pay tax and fight for our country, but are still set to be denied the same right to basic help with housing costs as any other British adult. There is simply no precedent for stripping away all support from our adult citizens in this way in the social security system at present.

Labour in government would do things differently. We’d reverse this cut which independent estimates suggest will save next to nothing once the knock-on costs of support for young people are taken into account. We’d also put into action the plan I’ve set out for Labour to end the scandal of rough sleeping within our first parliament. Homelessness is not inevitable in a country as decent and well-off as ours; it is the direct result of political decisions like this one.

If the Tories want to halt rising homelessness, they should start by cancelling crude cuts like this which make the problem worse. After seven years of failure on housing, today marks another step in the wrong direction.