Uk protest singers? Can't comment too much on the scene in other areas but certainly Glasgow still has some people singing out in protest.
How about Alastair Hulett? Check out both his "Red Clydeside" and "Sleepy Scotland" CDs for more info.

I noticed mention of the anti-war protests that took place last year. My wife's choir, the Eurydice Choir, took part and marched all the way from Glasgow Green to the SECC singing many of the protest songs mentioned previously. I was heartened to see so many young faces in the crowd that day, lots of whom were coming over to listen in and join in with the singing.

As for other protests and singers, there was also the Govanhill Pool campaign which was trying to prevent the (labour!) council from closing down the local swimming pool. A CD of protest songs appeared as a result of that. Other individuals such as John Mcreadie, Ian Davidson and Kenny Caird locally continue to write and sing songs of protest and struggle.

I still actively hunt out and sing protest songs as I feel they still have a resonance and relevancy today (le plus ca change?)

Whilst there may not be as much protest singing taking place as before, I would caution against being over nostalgic about just how active and politicised people were in the past. As has already been asked, just how did Nixon get elected if everyone was "protesting"?

Andymac