A House of Lords committee that suspended a Liberal Democrat peer who it found had sexually harassed a women’s rights campaigner has defended its decision, after the upper house voted to block the punishment.

The privileges and conduct committee, which announced last week that it was suspending Anthony Lester after finding that he tried to pressure Jasvinder Sanghera into having sex with him by promising her a peerage, said its inquiry into the matter “accorded with the principles of natural justice and fairness”.

The committee, which met to discuss its next steps after a debate in the Lords last Thursday to confirm the planned suspension until June 2022, instead voted to accept an amendment from a fellow lawyer and friend of Lester, David Pannick, saying the process had been unfair. The move prompted Sanghera, a longtime campaigner against forced marriages, to say she felt “victimised all over again”.

Female peers complained about the tone of the debate, which saw Pannick and others question why Sanghera had been cordial to Lester after the alleged harassment. On Tuesday, more than 70 Lords staff wrote to the Times saying they were “dismayed” by the vote.

After the committee met on Tuesday, its chair, the former Labour MP John McFall, said the members – who include the Tory, Labour and Lib Dem leaders in the Lords – “reconfirmed its view that the process undertaken to investigate Lord Lester’s behaviour accorded with the principles of natural justice and fairness”.

McFall said the investigation into Lester by Lucy Scott-Moncrieff, the upper house’s commissioner for standards, “was carried out entirely in line with the House of Lords code of conduct under which the complainant, Jasvinder Sanghera, made her complaint, and which all members sign up to at the start of each parliament”.

Allies of Lester have argued that the system was flawed because it did not allow for the peer, or his representative, to cross-examine Sanghera on her evidence.

The committee, McFall said, “will reflect on the amendment passed in the house last Thursday and the points raised in the debate and we will bring a further report to the house that more fully explains our position as soon as possible”.

Sanghera had told the inquiry that the harassment took place 12 years ago after she attended a meeting at the Lords and missed her evening train. Lester, now 82, suggested that she stay at his London home.

He groped her thigh while driving her to the house and made suggestive remarks, she said. The next morning, when his wife had left, Lester chased Sanghera around the kitchen, she said.

It was at a later meeting at the Lords, she said, that Lester made the offer to make her a baroness. She told the inquiry: “He even spelled it out, putting my surname in, and asked me how that sounded.”

The report said Sanghera provided six witnesses, among them a judge, who were able to say she had described the events immediately after she said they had taken place.

The debate about the suspension saw Pannick note that after the alleged harassment, Sanghera had written to Lester “in affectionate terms” in a book she gave him, saying this was inconsistent with her claims.

This prompted an angry response from Lady Jones, of the Greens, and the Lib Dem peer Meral Hussein-Ece. Jones said: “I actually walked out of the debate at one point because I was so horrified at the things that were being said – so misogynistic [and] victim-blaming.”