A letter from 100 current and former Labour members of staff calls on Jeremy Corbyn to “get our house in order” over claims that a senior aide accused of harassment was not suspended from the party on the advice of the Labour leader’s chief of staff.

David Prescott, the son of the former deputy prime minister John Prescott, was suspended from his position in Corbyn’s office in 2017 after allegations were made against him by a Labour MP, but he retained his party membership. Concerns were also raised about alleged behaviour towards two students, as reported by the Sunday Times at the time.

He has strenuously denied the allegations, no formal complaint was pursued and Prescott returned to his role in the Labour leader’s office.

Leaked emails suggested Corbyn’s chief of staff, Karie Murphy, told senior Labour officials she did not believe there were grounds for suspending Prescott’s Labour membership to bar him from attending party events.

On Tuesday, Labour staffers wrote an open letter to Corbyn asking him to overhaul the system.

In the letter, first reported by the Times, they wrote: “Working in politics isn’t easy, and many of us choose to give up our personal lives for Labour because we believe it is the best force for good in our country. What makes the job even more challenging than it should be is having to work in an environment where sexual harassment and bullying are not taken seriously.”

The letter calls the reports about Prescott “extremely concerning” and said they needed urgent clarification as to whether the account in the Sunday Times was correct.

“Clarity, consistency and transparency must be put at the forefront of the complaints process so that all sides feel confident that investigations will be conducted free from political interference,” the letter went on.

“The perception can no longer be that your connections within the party will determine whether complaints against you will be pursued or not. We want to see Labour in government, but we need to get our house in order first.

“We should, and can, lead the way in challenging and eradicating sexual harassment and bullying in work environments. The decision to write this letter does not come easily, but believing in a political party sometimes means having to ask uncomfortable questions.”

Labour has said it takes all complaints extremely seriously. “In this case, no formal complaint was received to investigate,” a party spokesman said.

“We do not comment on individual staffing matters. As an employer, the Labour party takes disciplinary and grievance matters extremely seriously and follows protocol as directed by the Acas [conciliation service] code of practice.”

MPs have urged the party to make its complaints procedure entirely independent to avoid accusations of factionalism in dealing with complaints of harassment or racism and antisemitism. The MPs Jess Philips and Stella Creasy have said the party must carve off its complaints arm, rather than use the current system where the bodies making final decisions about the complaints can be elected on factional slates.