How does the doctrine of British Baptists compare with their American cousins?

This question examines the difference between the American Baptists and Southern Baptists in the USA. In the UK, there is one formal Baptist denomination, the Baptist Union of Great Britain (BUGB). How does BUGB doctrine compare with the American equivalents? Which is it closer to? (The principle difference between the American denominations seems to be that the Southern Baptists encourage re-baptism while the American Baptists don't; the BUGB website doesn't seem to comment on this).