Hops are essential in brewing beer - nearly every beer. Contact your local brewery to source some hops, or Google.

Why? It is the most awful thug that you can imagine. Rampant growth which dies away in autumn and will neither decompose nor rot away. Seeds itself all over the place too.

in the UK brewers buy the hops in so wont have plants for sale. They grow specific varieties and the one that Canalhopper wants isn't one used in brewing.

Crocus list them but as unavailable and this could be due to the time of year. E-mail them and see when they will get them in again. There are several nurseries that list them but I suspect it is a bit late to be planting them.

Thompson and Morgan profess to have some,but I wouldn't recommend them as a supplier. However, Jackson's Nurseries have what they call a dwarf golden hop which appears to reach 2 - 2.5m, not sure if that's good enough, link below

https://www.jacksonsnurseries.co.uk/humulus-lupulus-golden-tassels.html

I've bought loads of plants from them over the years, they're usually pretty good.

Thanks for all the comments.
I really do want something that will cover the pergola and fast.
At one end I have a trachleospermum jasminoides and it’s growing, but painfully slowly & I have a honeysuckle and that’s taking its time.
I also have a wisteria in the middle, but that’s only been in a year.
We want to be able to sit in dappled shade, and we’ve been waiting for four years,

If you've already got Trachelospermum, honeysuckle and Jasmine, I think its a really bad idea to add a hop to the mix. With the three you've already got, once they get going, it won't be dappled shade, it will be total shade and you may require a machete...😉

There are some annual climbers you could have used; Tropaeolum peregrinum (canary creeper) or Eccremocarpus scaber grow rapidly and cover a good area in a season. Both are usually killed once winter arrives, although Eccremocarpus sometimes survives. You may be able to find one or other growing in pots at garden centres - they grow really easily from seed, but its a bit late for seed now.

Thank you Bamboo.
We went to a local nursery this morning and bought a grape vine instead! Now I shall need advice about that, but I’ll post a new question, with a photo.