Consider two aspects of modern Britain which are going to be much- discussed in Brighton next week.

The first is the “gig economy” – the convenience of having your takeaway delivered piping hot by Deliveroo, or that book you’d been looking for, delivered overnight by Amazon. But spare a thought for the man (and it usually is a man) who rushes to your door, makes the delivery and rushes off. Rude? No, just someone who is under incredible pressure to keep delivering.

Recently I grabbed a hurried word with a delivery man. He told me he was scheduled to make nearly 100 deliveries that day – almost impossible, at least impossible to do safely. And he, like many, was working for an agency that employed staff on zero hours’ contracts at minimum rates of pay.

The second aspect of modern Britain up for discussion is that last year membership of trade unions was half the level it had been in 1979 and is now at its lowest since modern records began. Days lost through strikes are equally low, as they have been for the past two decades – now one of the lowest levels in Europe.

The Brighton connection? The annual Trades Union Congress opens on Sunday at the Brighton Centre.

Being positive about trade unions is not always easy in Brighton – particularly among train users or those used to seeing union bosses flexing their political muscles in front of the cameras at Labour Party conferences.

But neither the 16-month rail dispute, nor muscle-flexing union bosses are typical of the day-to-day work of the trade unions as the subjects for discussion next week in Brighton reveal. Brexit, the environment, low wages, safety at work, Grenfell Tower and many of the other issues that concern those of us worried about what is happening in Britain today are up for discussion.

Why are so few people joining trade unions? Public opinion polls show up to eight out of ten of us think they are essential to protect workers’ interests – and never have those interests been in more need of protecting.

Zero hours’ contracts give employees no guarantee of work but usually require them to make themselves available should there be work be for them to do. Virtually none of the employers in the gig sector recognise trade unions, so workers have no one to turn to when they need help. Union membership is an age thing. Two out of five union members are over 50 which means retirement and death are increasing the rate of decline.

But it’s an age thing at the other end as well. Young people, in general, are just not joiners; they prefer to dip in and out as it suits them. Gym membership, for example, used to be a matter of signing up for a year, now you can join for a day, two days or even a month – annual membership is almost a rarity.

It’s also a matter of place. With the prospect of getting a foot on the housing ladder becoming ever more distant, young people are losing their attachment to place. What’s the point of joining something locally if, in a year’s time, you live somewhere else?

But maybe they should think again, for something very precious is being lost and that is the sense of belonging that union membership gives – something we saw after the Grenfell fire on the streets surrounding the tower block but it’s becoming rarer.

Trade unions are about belonging – identifying with fellow workers either linked by place or industry and it’s one of the ties that creates a stronger society.

Many years ago I was helping train journalists in Russia. They were complaining to me that even though Communism had gone, the new politicians and proprietors were just as reluctant to allow them to report freely. I explained that in the UK the National Union of Journalists was one of the strongest protectors of press freedom.

They found it difficult to grasp the idea that a union could be anything more than a creature of the government or their bosses. It made me realise how important unions were in creating strong societies.

No one should be forced to join a union but a society where more people are organised into unions is a healthier society.

None of which means returning to the Britain of the 1970s; but it could mean making Britain more like the countries of Scandinavia which are generally happier and more cohesive societies than our own. There rates of union membership vary between 50 per cent and 60 per cent of the workforce. Here it is about 20 per cent. The TUC message next week should be, and might well be, join a union – we’ll all be better off.

Ivor Gaber is professor of political journalism at Sussex University and a life member of the NUJ