Kate Hoey has announced she will stand down as a Labour MP at the next general election.
Announcing her plans, the MP for Vauxhall shared a picture of a letter addressed to her constituents, captioned: "Whoever is fortunate enough to be the next MP for Vauxhall I wish them well."
In the letter, she said she would continue to serve with "energy, honesty and integrity", but would not "seek re-election as a Labour candidate" in 2022.
"Until the next general election I will of course continue every single day to give my all to help constituents in Vauxhall and to campaign for policies that make life better for residents," she wrote.
The Brexiteer was elected to the Vauxhall seat in 1989, and served as a junior minister in the Home Office and Department of National Heritage during her time in Parliament.
She said it was a "huge privilege" to represent Vauxhall.
Since her announcement, a number of people have speculated whether she will join the Brexit Party.
Twitter user Hugh Bennett tweeted: "Interestingly Kate Hoey only rules out seeking re-election as a Labour candidate, could a shock defection to the Brexit Party be on the cards?".
And Brexit supporter Chris Leigh wrote: "Please join the Brexit Party. We desperately need your experience if and when the British people take back control of our democracy. We need people that believe in Britain."