The Election Project, Simon Roberts exhibits at Portcullis House

Westminster Village hosted Open House last weekend and a significant attraction was at Portcullis House where two linked photo exhibitions, The Election Project and The Public Gallery are on show until Christmas. The main works, 25 large colour prints by British photographer Simon Roberts, follow the campaign canvassers around the UK during the final 25 days before the general election, while the amateurs’ collection is a frieze of 1,696 postcard-sized digital prints of images sent in response to requests made at each stop.

Simon Roberts is known for epic, poetic landscapes serving as backgrounds to human vignettes. His style is epitomised by the celebrated 2009 book We English, which contributed to his selection from 17 other candidates by the Speaker’s Special Advisory Committee of Works of Art. He told them that he would travel by Motor Home and shoot, as usual, with a large 5x4 plate camera, but now fixed on the roof. He dismissed a catalogue or book in favour of a newspaper and informed them that he would involve the public, “engaging the public in the political process through photography”. He got the job. That high vantage point allowed a bigger perspective than was achievable by the press pack, and as this to be the most photographed election ever, in this era of 24-hour news cycle, he said, positioning was crucial.

Roberts’ signature approach works beautifully in this context: “I wanted it to be a snapshot of the landscape in the same way of We England,  he explained, “A political theatre with the backdrop of the landscape of Britain, 2010.” The compositions are carefully planned but details of the dramas being enacted were, of course, unpredictable. He watched as Gordon Brown’s small-scale meeting in Rochdale turned into “Bigot-gate” (pictured above), Gillian Duffy looking insignificant but ranting, in a mundane setting near council houses and a woodland path where ex-offenders are cutting trees. Sue Nye is calming Duffy, and a security man is feeling for his gun: a perfectly choreographed film still. It is beautifully balanced by the Public Gallery snapshot of Brown’s pained expression after apologising later.

After that, those shoots with the future Coalitionists - Cameron walking with his pregnant wife through an idyllic, middle-class Oxford village and Clegg soap-boxing to a small crowd in a Tesco carpark - seem mundane and fake. Whereas the Public Gallery offers an endlessly fascinating visual soundtrack to a country still under Labour leadership: witty, bitter, betrayed, inspiring and mundane images, they perfectly complement Roberts’ sophisticated versions of he describes as “the kinds of things I would never have thought of photographing.” They will all add significant information as socio-political documents of the age – including the man in his kitchen holding up a note reading Mr. Brown Sucks, a billboard reading Our Dreams don’t fit on your ballots, and a BNP flyer in a drain (pictured above).

Shame, then, that in spite of Roberts’s successful "democratising the political process through photography"' the exhibition is only on show to the public for two days. There are plans to tour it "next year" but who knows what tricks fate will have played on the characters in these photographs by then.

• Visit the Westminster Open House website
• Find We England on Amazon