Labour has stepped up its investigations into allegations of inappropriate behaviour against two MPs.
The men were among a number of Labour and Tory MPs to be investigated after allegations of Westminster sleaze last year.
Commenting on Mr Lewis’s case, a Labour spokesman said: “After consideration of statements provided by the complainant and the respondent, the NEC’s (national executive committee) sexual harassment panel has agreed that on the balance of the evidence the matter should be referred to a full hearing of the national constitutional committee.
“The Labour Party will not be commenting further on this case until the conclusion of that hearing.”
The party issued a similar statement regarding Mr Hopkins.
Mr Lewis was suspended in November following a complaint about his conduct.
Earlier that month BuzzFeed News reported that a woman alleged the Bury South MP had touched her leg and invited her to his house when she was 19 at a Labour Party event in 2010.
A statement issued through his lawyers at the time said Mr Lewis had “never made non-consensual sexual comments or sexual advances to women”.
He added: “However, I understand that a few women have claimed that my behaviour made them feel uncomfortable. I have on occasion asked women I work with out for drinks or dinner, or developed strong feelings for them, and I am genuinely sorry if this was unwelcome or inappropriate in the circumstances, and caused anyone to feel awkward.”
Former shadow culture secretary Mr Hopkins has denied allegations made against him.
Ava Etemadzadeh, 27, claims that the 76-year-old Luton North MP acted inappropriately and sent her suggestive text messages after they met at a student event in 2014.
Mr Hopkins was reprimanded after Ms Etemadzadeh initially complained in 2015, but was later promoted by Jeremy Corbyn to his shadow cabinet.
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The long-serving left-winger is now suspended from the party pending investigation of Ms Etemadzadeh’s complaint and separate allegations by MP Kerry McCarthy of unwanted attention over a number of years.
Ms Etemadzadeh said: “After two long years of my complaint about Kelvin Hopkins being ignored by Jeremy Corbyn, I cautiously welcome the fact that my case is finally being heard.
“I’m grateful to the NEC panel for recognising that there is a case to answer here and the matter should be referred to the National Constitutional Committee for consideration of disciplinary action.
“But this doesn’t hide that the facts of my case haven’t changed since I made my original complaint in December 2015.
“The only reason this case is being heard by the Labour Party is because I went public and the resulting media backlash meant that what had been covered up before, would now be examined.
“And while I had been fobbed off without any action, Kelvin Hopkins found himself rewarded by Jeremy Corbyn with a shadow cabinet spot.
“I know the NEC will take its responsibilities seriously, act with integrity, and I look forward to finally having my say.
“But the only way victims of harassment in politics can see justice is through the establishment of an independent politically neutral body.
“Without such a body, there will always be the risk of the sort of political meddling we have seen in cases like mine, and women in the Labour Party will not be safe.”