Luton North Independent MP Kelvin Hopkins has announced he is stepping down ahead of next month's general election.
Mr Hopkins is currently suspended from the Labour Party after harassment claims were made by activist Ava Etamadzadeh.
He has served as MP for Luton North since 1997.
In a statement, Mr Hopkins said: "My wife Pat has been seriously unwell this year, with seven weeks in hospital and ongoing medical treatment, and needs a degree of care and support which I could not give while spending long days and nights in Westminster and in a Parliament which could last another five years.
"I have been greatly honoured and privileged to represent the fine people of Luton North and indeed the great town of Luton in Parliament for over 22 years, but now I have to pass that role on to a successor.
"Luton has been my home for over 50 years, a town I love and which I hope to continue to support in other ways.
"I have received the most wonderful support from my constituents and my local Labour Party during my time as their MP and I am eternally grateful to them all.
"I have also been supported for all my 22 years in the House of Commons by a brilliant team of staff, and I have to give them my particular and enormous thanks.
"Politics is a lifelong passion and so to be able to pursue that in Parliament has been a rare and fascinating experience. I shall continue to write and speak about politics, seeking to advance the causes that i believe in and the particular interests of working people across Britain and the world.
"I look forward to seeing Labour in office again, with Jeremy as our Prime Minister. He is a dear friend and the most decent and principled leader in Parliament, someone who cares about the many not the few, the mass of ordinary people rather than the billionaires and the bankers.
"With inequality and poverty growing, there is much to do, and we desperately need a government that will address all the ills, the insecurities and the injustices which still exist in the modern world."