The former deputy speaker of the House of Commons Nigel Evans used his "powerful" influence to sexually assault seven young men, a court has been told.
The MP had the "ability to make or break" the careers of those who wished to work in Westminster, a jury at Preston crown court heard.
Evans exploited his position and pressed his sexual attentions on his victims, and carried on doing so despite being warned about his behaviour, said the Crown.
Evans, 56, faces nine charges, dating from 2002 to 1 April last year, involving the seven complainants.
The MP for Ribble Valley in Lancashire denies two counts of indecent assault, six of sexual assault and one of rape.
Opening the case, the prosecutor Mark Heywood QC said: "Within the Palace of Westminster, in his constituency and in his own political party, Mr Evans was, during the decade with which you are concerned, a very well known and powerful individual.
"Part of his influence included the ability to make, or to break, the careers of those young people who themselves would be politicians or work for those who govern.
"The prosecution case against Mr Evans is that he, often when in drink, pressed his sexual attentions on those younger men, using or trading on his position of influence.
"Now this behaviour did not happen once but has been repeated over time and despite repeated warnings given to him by others.
"It has also escalated in seriousness, no doubt because he believed that his position made it less than likely that someone would complain."
Heywood continued: "The prosecution alleges that he, on separate occasions over many years, has sexually assaulted young men, both in public situations and in private.
"In early 2013, he raped one of the young men.
"So the prosecution allege, he not only abused those young men, in some cases seriously, but he abused the positions he held.
"Mr Evans, on the other hand, denies the allegations made; he says that in respect of, for example, the rape, events were entirely consensual, agreed upon, or the result of misreading signals or simply that either they did not happen or he has no clear recollection because of the passage of time."
Heywood then began to go through each of the allegations individually.
The first alleged offence happened in late 2002, with the complainant a gay man aged 27. One evening he was in a busy Soho bar, either the Red Cube in Leicester Place or the Green Carnation, the jury heard, and Evans was also there.
"He had obviously had quite a lot to drink," Heywood said of the MP.
"Whilst the complainant was standing talking to someone else he felt a hand going down the back of his trousers. The defendant placed four fingers inside the waistband of his trousers, reaching down as far as the web of the thumb would allow.
"So you understand, there were no words, no warning or invitation. The complainant neither wanted nor consented to the act.
"He was shocked by it but, and this is, you will see repeated over time, he did not want to cause a fuss because of who Mr Evans was."
The complainant was annoyed but walked away and felt "sorrow" at the MP's behaviour because while it was known he was gay, at that point he was not "openly gay" and the wider public did not know this, the court heard.
The second complainant was assaulted one night at the Conservative party conference in Blackpool in 2003, in a bar called Number 10 within the Imperial Hotel.
He was drinking with a friend, at some time between midnight and 3am, and Evans was there and described as being "plastered", Heywood said.
The trial continues.