Photography nuts will already know Peter Kennard as one of the most influential photographic artists alive. For others, think of an artist along the lines of Michael Moore, John Pilger and Banksy - left wing, high-profile and politically motivated.

If you haven't seen Uncertified Documents - the retrospective of Kennard's career at Pump House Gallery - then take heed because this is its last week on show.

The 30-year span of Uncertified Documents shows Kennard's imaginative and witty treatment of war, the environment, nuclear disarmament and civil liberty, including the whole process from early roughs to published final.

Speaking on his career, he says: "My work comes out of anger with the world, and it always has done. I was against the Viet Nam war and the show goes up to now with the invasion of Iraq.

"I try to express anger but in an accessible way to try and get through to people."

The world has changed hugely since his Heath-era work. An anti-war and nuclear power stance was considered subversive, and "gave voice to those who are increasingly marginalised and silenced".

But these are popular views now, making it more difficult for him to avoid preaching to the converted. Hence why he crops up in an increasing variety of places. "I'm a nebulous figure who turns up in funny places," he states.

Another hurdle he has had to overcome is the proliferation of digital technology, which allows your Gran to get bang into her photomontage, if she so wishes.

Nevertheless, Kennard is no Luddite, and has embraced digital technology through collaborations with a bright young thing of photography, Cat Picton Phillipps.

One of Kennard's most striking images in Uncertified Documents is Battersea (1983), which depicts a plug plunged into the top of Battersea Power Station.

"That was about renewable energy and factories becoming socially useful products which reuse their energy," says Kennard, "that was an attempt to visualise that idea.

"The station was still in use, pushing out all this smoke and it seemed like a strong symbol and an iconic building people knew."

Again, how things have changed. twenty five years later, renewable energy has gone from marginal to global issue, and while Kinnock's Labour party used the Battersea image for its anti-nuclear message, Brown's Labour is throwing billions behind nuclear power.

Uncertified Documents; Pump House Gallery, Battersea Park; until March 30, open Weds-Sun, call 020 7350 0523.