Interlay are the closest thing we have to an "official" trade association for block paving contractors. Unlike certain other groupings of paving contractors, they are not affiliated to a single manufacturer but are part of the British PreCast Concrete crowd, which includes Interpave, the trade body for block paving manufacturers. As you'd expect, their laudable aims include promoting "best practice" and presenting a more professional image of the contracting industry.
For one reason or another, they've never really promoted themselves properly and to my way of thinking it's worrying that "brand awareness" amongst contractors is so low compared to that of the other contractor lists, so I've agreed to "big them up" and attempt to bring them to the attention of the wider readership enjoyed by the Pavingexpert website. To that end, here's a copy of their latest newsletter: it's a tad out of date (the new issue is due quite soon) but there's some intersting stuff therein that will appeal to many contractors.