Keith Vaz bullied Ms McCollough from 2007 to 2010.
An investigation has found that Keith Vaz bullied a female government clerk in a “hostile, sustained” and “harmful” way.
The former Leicester MP also likened her to a prostitute.
The Independent Expert Panel’s (IEP) report came after the Parliamentary Commissioner for Standards concluded that Mr Vaz had breached the bullying and harassment policy in his interactions with Jenny McCollough on several occasions between July 2007 and October 2008.
Ms McCollough worked as a clerk on the Home Affairs Select Committee that Mr Vaz chaired at the time.
Mr Vaz failed to engage in the investigation due to claims over ill health, with the inference that the investigation should be dropped.
The panel did not dispute he was in ill health.
However, his “ongoing public media and political activity” including regularly presenting a radio programme, writing columns for the newspaper Asian Voice, and issuing other comments and statements, meant they did not believe he had been unable to engage with the process.
The report detailed how Keith Vaz bullied Ms McCollough from 2007 to 2010.
This included inappropriate anger, loud and aggressive speech, and demeaning her in front of others.
On a trip to Washington in 2007, Mr Vaz told Ms McCollough to perform like a ‘tour guide” in front of the visiting part in a bus.
The report stated that on a trip to Russia in 2008, Mr Vaz insisted on having a member of his own staff, despite being advised against it.
He then told Ms McCollough this was because she was “not competent”.
Mr Vaz then threatened to take photos of her drinking alcohol and show them to her manager.
According to the report, there was evidence that the photos were taken and “the implication of the threat was that she was liable to drink to excess so as to affect her performance”.
The panel found “there was no substance to this” and deemed it a “psychological threat”.
On the same trip, Mr Vaz told her she could not do her job because she “wasn’t a mother”. He also forced her to reveal her age in order to undermine her performance.
After Ms McCollough had moved to a different team, Mr Vaz told her that after a meeting with prostitutes, they had “reminded him” of her.
Due to the bullying, Ms McCollough quit the House of Commons in 2011.
The IEP ruled that Keith Vaz should never be allowed to hold a parliamentary pass.
IEP chairman Sir Stephen Irwin said Mr Vaz “should be ashamed of his behaviour”.
Dave Penman, general secretary of the FDA union, which represents parliamentary staff, said Ms McCollough had “not only shone a light on reprehensible conduct and behaviour of a senior member of Parliament, but also the inability of both Parliament and political parties to address these issues in the past”.
He said: “The report could not paint a clearer picture of sustained, inappropriate conduct that not only caused harm to a committed public servant but caused her to leave the service.
“This conduct would have been visible to fellow MPs, whips and senior managers in parliament.
“The unwillingness of Parliament to address these issues before now should weigh heavy on all who had the opportunity and power to address them at the time.
“It’s clear that an independent process was – and remains – necessary to ensure this kind of behaviour does not go unchallenged.”