1 May 2012
Following his successful first appearance on the show last year, Mark will join work and pensions secretary Iain Duncan Smith and Labour's deputy leader Harriet Harman on the panel.
It comes a week before our joint national strike over pensions on 10 May.
The long-running programme, aired on BBC1 at 10.35pm on Thursdays, is hosted by David Dimbleby and involves members of the audience putting topical questions to the panellists.
As well as two to three million people regularly tuning in, Question Time has developed a large following on the social networking site Twitter, with users using the 'hashtag' #bbcqt to share their thoughts.
Mark first appeared in the week following the March for the Alternative in London on 26 March last year. In January, he was a panellist on BBC Radio 4's Any Questions?