Labour MP Kelvin Hopkins has been suspended from the party over allegations about his behaviour towards a young activist.
The MP for Luton North has had the whip withdrawn while an investigation into claims he sent suggestive texts and acted inappropriately is carried out.
Mr Hopkins is the latest MP to become caught up in a wave of allegations over sleaze in Westminster.
Mr Hopkins, 76, has been an MP for 20 years and has remained on the backbenches except for a four month stint as culture spokesman last year.
It is understood that Mr Hopkins was spoken to about why his behaviour was inappropriate and reprimanded by then chief whip Dame Rosie Winterton.
A spokesman said: "On the basis of allegations received by the Labour Party today, Kelvin Hopkins has been suspended from party membership, and therefore the Labour whip, while an investigation takes place.
"The Labour Party takes all such complaints extremely seriously and has robust procedures in place to deal with them."