Neil Parish has told the BBC he is resigning as an MP after admitting he watched pornography twice in Parliament.
Mr Parish, who has represented Tiverton and Honiton in Devon since 2010, said it had been a “moment of madness”.
Two female colleagues claimed they had seen him looking at adult content on his phone while sitting near them.
“I did get into another website that had a very similar name and I watched it for a bit, which I shouldn’t have done.
“But my crime – biggest crime – is that on another occasion I went in a second time.”
He admitted that second time had been deliberate and that it happened in the House of Commons while he was sitting waiting to vote.