There are well made, very similar to the one's Hackett and Aquascutum have; I would not be surprised if they same place made jeans for all three.Gieves & Hawkes.
I don't know who makes them for them but they are fantastic jeans.
The only thing I do not like is the colour, the shade is too dark for me, otherwise I would get my jeans from there.
The jeans do go well with a sports jacket. Far too many people in London walking in badly fit jeans, sportscoat and white shirt.One model a year, great denim quality, well constructed, VERY conservative (the type of jean you can wear with a sports jacket as opposed to fashion forward/discothèque wear.
They stopped the Gieves range; although I liked the style, the material was cheap.They are the only jeans I wear now and I doubt I'll buy any other type until they stop making them.
Note though that these are Gieves & Hawkes and not their "Gieves" line.