They were following in the footsteps of Brian Paddick and Boris Johnson who have arrived at the company's Cheam headquarters in recent weeks to answer a battery of questions from reporters and readers of local newspapers and websites.

With a million and a half readers across south London, the political parties have woken up to the importance of Newsquest's news operation south of the river, centred on the South London Guardian.

Coming to answer questions centrally, from a dozen reporters working on a range of titles, they realised it was a good way to get their message out with maximum impact and minimum effort.

The Tory leader's impromptu visit this week was confirmed late on Monday – two days before the publication of the company's weekly print titles, which cover south-west London and Surrey.

A story was posted online at yourlocalguardian.co.uk asking readers what questions they wanted to ask the man bidding to be the next Prime Minister. The internet proved crucial in allowing readers to submit their questions in time.

He was filmed as he was in the hot seat answering questions on immigration, education, council tax and the environment, as well as the priorities for a Conservative Government.

Ken Livingstone was probed about his time working as an orderly doing medical research into childhood leukemia in Sutton - he had no qualms about experimenting on rats if it helped save children.

Group editor for south west London, Sean Duggan, said: "It has been a fascinating process watching these men at close quarters respond to the concerns of local people.

"All of them are consummate politicians, and our reporters sometimes had to work hard to get beneath the pat, well-polished responses.

"Both in terms of understanding their policies and providing answers for readers to help them to decide how to vote on May 1, getting the politicians in here has been a resounding success."

Senior web reporter Daniel Knowles, who filmed David Cameron's visit, said: "We set up one of our laptops logged on to our two sites using a mobile internet card and put David Cameron in front of it.

"While he checked the questions coming in in real time, we filmed the piece with two cameras – the main one in front and the second giving an over-the-shoulder shot of him checking our sites.

"We let the video run on longer than usual so readers could see all their questions answered and judge him by his own words."

To see the video footage of David Cameron - edited and online less than 30 minutes after he left - click here.

Submitting Information

Click here to have your say on this story