Labour MP Dawn Primarolo has announced she will stand down at the next election.
The Deputy Speaker told members of her constituency party her decision at a meeting on Thursday evening.
She said it had been a "huge honour" to be the MP for Bristol South since 1987. "I wanted to give as much notice of my intentions as possible, but I can assure Bristol South residents that I will still be working as hard as ever from my office in Bedminster to improve our communities right up until the day of the next General Election."
Before becoming deputy speaker in 2010, Primarolo was a minister during the Labour government in the Treasury, Department of Health and Department for Children, Schools and Families.
Labour leader Ed Miliband said she had been a "fantastic" MP : "I have worked closely with Dawn for almost fifteen years. She has served the Labour Party and our country well as a Minister in the Treasury, Department of Health and Department for Children, Schools and Families. Now, she is respected by MPs from all parties in her work as Deputy Speaker. Above all, though, Dawn has always put her constituents first. She has been a fantastic servant to the people of Bristol South, and I know that she will continue to fight hard for the residents of Bristol South in the coming years."