Neil Parish, who had the Conservative whip suspended on Friday, admitted he had opened a file by mistake, but said he would continue his parliamentary duties pending the outcome of an investigation.

However, in the face of growing pressure the MP for Tiverton and Honiton, his local Conservative association said he had agreed to step down.

A spokesperson for Tiverton and Honiton Conservatives said: "We would like to take this opportunity to thank Neil Parish for his service to our communities over the past 12 years.

"We support his decision to step down as our Member of Parliament."

Friends of the 65-year-old are said to be unhappy at the way he kept quiet and allowed speculation to form about party colleagues, according to Sky News deputy political editor Sam Coates.

The former farmer and MEP referred himself to the Parliamentary Commissioner for Standards, days after two female Tory MPs said they witnessed him watching pornography on his mobile phone on two separate occasions - once in the Commons chamber and another at a committee.

The departure of Mr Parish, who also chaired the Commons Environment, Food and Rural Affairs Select Committee, will trigger a by-election in what has been a safe Conservative seat.

Mr Parish, who had represented the Devon constituency since 2010, was returned in 2019 with a majority of of 24,239, securing 60% of the vote.