Tom Watson, the Cabinet Office minister for digital engagement, is stepping down from the government before the next re-shuffle, expected this Friday.
Watson is expected to say he wants to spend more time with his family.
His departure comes just weeks before the government's Digital Britain report is published.
He was linked to the expenses disclosures after claiming the maximum allowed for food, and was also dragged into the Damien McBride emails scandal after the Mail on Sunday published an article linking him to it. He won damages in court against the newspaper, as well as a retraction.
He was the first MP to set up a blog and is a prolific user of Twitter, but has not commented on his departure on either.
Watson has commented and campaigned on technology-related issues during his time in office, including broadband and the importance of the gaming industry to the UK economy.