Suspended Labour MP Kelvin Hopkins has said he "absolutely and categorically" denies claims of sexual harassment.
Labour activist Ava Etemadzadeh, 27, earlier told the BBC that Mr Hopkins had hugged her inappropriately after a student event in 2014.
Denying the claims, Mr Hopkins said he had only "put an arm around her" and did not hold her tight.
Meanwhile, Labour MP Clive Lewis has denied groping a woman at the party's annual conference this year.
A party member told the Independent newspaper how Norwich South MP Mr Lewis allegedly groped her at the party conference last month.
Labour said it was investigating a formal complaint against Mr Lewis.
However, in a statement, the former shadow minister said: "I know how I roll. I don't squeeze women's buttocks."
He told BBC News he was "vigorously" disputing the allegation, adding: "I'm feeling pretty taken aback by it all."
"I'm a friendly person, I'm someone who enjoys the company of people and it saddens me that I will now have to think about standing back, about being more formal," he said.
The claims against Mr Lewis come after Luton North MP Mr Hopkins was suspended by the party on Thursday while an investigation takes place.
Ms Etemadzadeh alleges that Mr Hopkins said during a conversation in Parliament: "Let's not talk about politics, do you have a boyfriend?"
"He also said that if nobody was in his office he would've taken me there," she added. "I was absolutely shocked and I wasn't really expecting that."
After refusing to respond to his phone calls, she claimed he sent her a message saying "that I'm an attractive, lovely young woman and a man would be lucky to have me as a lover and if he was young... but he's not".
Mr Hopkins did not initially respond to the allegations.
However, in a statement issued by his solicitors, the 76-year-old denied claims he had acted inappropriately at the student event in 2014.
He said: "I simply put an arm around her shoulder to give her a brief, slight hug just before getting into my car.
"I did not hold her tight. I did not rub any part of my body, let alone my crotch, against Ava.
"She waved me off as I drove away and did not say anything whatsoever to suggest that anything had occurred that upset her, let alone revolted her."
Mr Hopkins said he did not recall asking her about her personal life, but said he did send a text message saying she was "charming and sweet-natured".
He admitted sending a message that said "a nice young man would be lucky to have you as a girlfriend and lover... Were I to be young... but I am not...".
He said she replied to the message.
Who is Kelvin Hopkins?
- Labour MP for Luton North since 1997
- Spent most of 20-year political career on backbenches
- Briefly promoted to front bench from July to October 2016
- Long history of involvement with trade union movement
- One of 36 MPs to nominate Jeremy Corbyn for his 2015 leadership bid
- One of the few Labour MPs to campaign for Leave in the EU referendum
- Married to Patricia. The couple have two grown up children
Ms Etemadzadeh said she raised her concerns about Mr Hopkins' conduct with another Labour MP, saying her complaint was passed to the party's former chief whip Dame Rosie Winterton, who responded to it.
But Ms Etemadzadeh said she was told she would have to waive her anonymity for action to be taken and the prospect of that "scared" her.
It is understood Mr Hopkins was verbally reprimanded about his alleged behaviour.
He went on to be promoted, albeit briefly, to Labour's front bench in June 2016 - shortly after leader Jeremy Corbyn faced mass resignations following the EU referendum.
It has emerged that Dame Rosie rang the Labour leader's office to ask why Mr Hopkins had been appointed to the shadow cabinet in July 2016.
A Labour source said she reminded them that Mr Hopkins had been reprimanded for harassing a young activist.
The Labour Party has not commented on the claim.
On Friday, it was announced that Labour will appoint an independent specialist organisation to offer advice and support to individuals affected by sexual harassment in the party.
A statement said the party will announce the organisation will take on the role "as soon as possible".
It also said that independent legal expert, Karon Monaghan QC, will investigate Labour activist Bex Bailey's allegations.
Ms Bailey has said she was raped at a party event and a senior Labour official discouraged her from reporting the attack.
She said she was told reporting the alleged 2011 incident could "damage" her and that she was given no advice on what she should do next.