Since the Modern Slavery Act of 2015, British companies over a certain size have been required to report on slavery in their supply chains. Their statements are both shocking and admirable. Shocking because they make clear that the incidence of slavery has become normalised once again – and not just in criminal operations such as the illegal drugs trade or trafficking for prostitution, but in the mainstream economy. The declarations are prefaced with management expressions of abhorrence, of course, but there they are, another note alongside the annual accounts. They are admirable, however, in that transparency must be the first step to tackling this phenomenon.

Last month the National Crime Agency reported a 35% annual rise in the number of suspected slavery victims found in the UK, with more than 5,000 people referred to the government mechanism that supports them in 2017. Labour exploitation, rather than sexual exploitation, was the most common type of modern slavery cited.

The list of high-risk sectors for slavery declared in company statements is long: temporary workers in distribution and office cleaning; agency labour in logistics operations; subcontracted car-washes cleaning company vehicles; construction workers building and renovating company premises; outsourced security staff. A catalogue of the casualised workforce, in other words. It is hardly surprising that the most egregious forms of exploitation should appear where economic, legal and moral responsibility has been deliberately diffused. Modern slavery is the flipside of the coin that has seen corporates offshore their profits and dodge tax. Both represent a sloughing-off of what were seen in the past as important obligations to society.

Then there are the more specific areas of production, where big high-street retailers’ statements acknowledge that forced or trafficked labour, often of refugees, is a well-known and recurring issue: the British and Irish fishing fleets, the UK meat and poultry processing industry, Leicester garment manufacturing, the Thai prawn supply chain, the Italian tomato industry, the Spanish horticulture sector, the Assam tea chain, and the Turkish garment sector.

Separate from corporate reporting, the Gangmaster and Labour Abuse Authority was given powers in April 2017 to investigate exploitation beyond its original narrow remit of food and agriculture. The more it looks, the more it finds, and some of this new activity accounts for the increasing numbers of suspected victims of modern slavery. (Another factor is the statutory defence introduced in the Modern Slavery Act for those forced into criminal activity such as drug dealing: increasing use of that defence in drug cases probably accounts for British victims unusually making up the largest number by nationality this year. Albania, Vietnam, China, Nigeria, Romania, Sudan, Eritrea, India and Poland make up the rest of the top 10 source countries.)

The main concentrations the GLAA sees are among migrant workers in hand carwashes, nail bars, domestic building projects such as basement excavations, the hospitality trade, hotel cleaning, takeaway restaurants and domestic cleaning.

How did slavery, which we thought was abolished, reach into our everyday consumption? While it is quite right that companies should have their reputational feet held to the fire for abuse that arises out of their economic model, there are also uncomfortable truths here for affluent consumers of personal services.

Things that were until recently luxuries – manicures, clothes that change fashion every few weeks, regular holiday breaks to hotels, eating out frequently, having your car hand-valeted, using manual labour to dig out a basement under your house – are now presented to us as affordable, everyday even. Where they have become so, it is in large part thanks to other people being badly paid at best, or victims of modern slavery at worst. The squeezed middle has been bought off by the illusion that it can share the consuming habits of those with runaway incomes at the top; but it can’t – not without squeezing those further down the chain.

If you are being offered a service for much less than you would expect to pay for it, someone is being exploited

In a world where the state has often absented itself from the enforcement of employment law, and where so many human interactions are reduced to financial exchanges at whatever rate the market will take, people have become commodities to use or sell. When competition and austerity are king, it is every man and woman for themselves and their family. Too often, we close our eyes and try to protect our own.

People-traffickers target the vulnerable – including those with learning disabilities or raised in care, homeless people, those with alcohol and drug problems or previous convictions. They are the people easiest to control and least likely to attract sympathy. Anti-immigration sentiment has encouraged people to see these victims as foreign, as “other”. How else to explain why neighbours, work colleagues and customers so often fail to notice modern slavery?

Take the group of trafficked Lithuanians working brutal hours on egg farms around the country who were kept under control in their Kent ganghouses by threats and fighting dogs. What did farm managers and local residents on the same quiet streets see and hear? Alarming antisocial behaviour, and fights in a foreign language that made them want to turn away and keep their heads down, or fellow human beings suffering intolerable abuse and anaesthetising themselves from the trauma with drink?

Both the National Audit Office and the parliamentary select committee for work and pensions have highlighted serious shortcomings in the support for victims of modern slavery once they have been identified. The anti-slavery commissioner, Kevin Hyland, also pointed out to the committee that every time a suspected victim of slavery is referred to the national referral mechanism, a crime is being alleged. Yet there is only a one-in-four chance of these cases being recorded as a potential crime, let alone investigated. If there were 4,000 rapes in the UK and only one in four was recorded by the police, there would be an outcry, he said. These failings need state remedies.

Meanwhile, we all need to recognise the signs. Where workers are putting in excessive hours, where they have no language to communicate with customers or where employers seem quick to speak for them, where they live in houses of multiple occupancy, we should be alert to the possibility of modern slavery.

If you are being offered a service for much less than you would expect to pay for it, someone is almost certainly being exploited. A car wash that takes six men 15 minutes and costs £10 does not pay the legal minimum wage. If something seems too cheap to be true, it probably is.

• Felicity Lawrence is a special correspondent for the Guardian