Disgraced Eric Illsley has said that he is quitting as an MP after being convicted of dishonestly claiming more than £14,000 in expenses.
The MP for Barnsley Central said he "deeply, deeply" regretted his actions and would be resigning before his sentencing next month.
In a statement issued by his office, Illsley said: "I would like to apologise to my constituents, family and friends, following my court appearance, for the distress and embarrassment caused by my actions that I deeply, deeply regret.
"I have begun to wind down my parliamentary office, following which I will resign from Parliament before my next court appearance. I will be making no further comment."
Illsley's decision to step down will be a relief to MPs who feared more damage to Parliament's already tarnished reputation.
The revelation on Tuesday that he could potentially receive his salary while in prison if a sentence of less than 12 months is imposed prompted both PM David Cameron and Labour leader Ed Miliband to urge him to go voluntarily.
There had been suggestions that the House could be asked to back a motion expelling the MP, which would have been the first time such a mechanism had been used in decades.
But Commons Speaker John Bercow has made clear that could not happen until court proceedings were complete because the matter was still sub judice.