Chris Rennard, the Lib Dem peer who was accused of sexual harassment by four women, has been elected to the party’s ruling body, in a move that has already prompted pleas for the party leader, Tim Farron, to intervene.

Lord Rennard, who has always denied any wrongdoing, was voted on to the Liberal Democrats’ federal executive by the party’s fellow peers.

It is understood Farron is not planning to speak out against the development, despite having said during his leadership campaign that he would not appoint Rennard to any position of power.

On Thursday evening Kat Bavage, a Lib Dem activist who helped run the Rock the Boat group against sexual harassment, resigned from the party on Channel 4 News. The group is circulating a petition calling for a special conference about Rennard’s appointment.

Separately, Sal Brinton, the Lib Dem peer and president, has written to members of the federal executive expressing her disappointment that Rennard put himself forward and making clear she did not vote for him.

The controversy over Rennard, the party’s former chief executive, engulfed the Lib Dems for more than a year. After lengthy inquiries, he apologised if he inadvertently made the “women feel uncomfortable”, but he has always categorically denied allegations of sexually inappropriate behaviour.

A QC-led investigation said there was insufficient evidence to warrant disciplinary action against him over allegations of inappropriate touching. A subsequent inquiry into whether had brought the party into disrepute by criticising its handling of the matter was dropped.

Two of the women involved, Bridget Harris – a former adviser to Nick Clegg – and Susan Gaszczak, a former councillor, resigned from the party when Rennard’s suspension was lifted in 2014.

It is understood at least one prominent female Lib Dem is poised to resign over the peer’s election to the executive and several have pleaded with Farron to intercede or at least publicly condemn the decision.

One member of the federal executive, Joshua Dixon, expressed his disapproval, tweeting: “What to even say in a situation like this. So disgusted at our Lords group tonight. … I came into politics to fight for social justice and equality, not to sit on committees with people like Rennard. Am I just wasting my time?”

Sarah Noble, an executive committee member of LGBT+ Lib Dems, said it was a “slap in the face to all female members of the party that Rennard is being welcomed back into the fold as if nothing happened”.

She added: “The peers should take a long hard look at themselves and not be surprised if the wider membership voice their disapproval to this ridiculous appointment.”

A Lib Dem spokesman said: “This was an internal election to find a representative from the Liberal Democrat group in the House of Lords to sit on the party’s federal executive. Any Liberal Democrat peer was eligible to stand for the position and any Liberal Democrat peer was able to cast a vote in the election.”