Media playback is unsupported on your device Media caption Not all Tories are convinced about the new code, as Vicky Young reports

The Conservative Party has issued a voluntary code of conduct to all its MPs telling them not to "bully, abuse or harass" their employees.

Staff were entitled to "work in an environment free from unwelcome behaviour and inappropriate language", the document says.

The move comes amid concerns over the working culture in Westminster.

Commons Speaker John Bercow has plans to launch a hotline for staff with concerns about bulling.

And an investigation by Channel 4 News, broadcast on Thursday, uncovered a "climate of sexual harassment" in a survey of parliamentary workers.

The programme said it had interviewed 70 people from "all political parties and sexual orientations", and found that incidents of sexual harassment and abuse of power in Parliament were commonplace.

Young men were more likely to be sexually harassed than women, it concluded.

'Three stage process'

A Conservative spokesman explained: "The code of conduct acts as a basic statement of what should be best practice in the workplace for Conservative members and their staff."

People are entitled to be treated with dignity and respect as they carry out their work John Bercow, Commons speaker

"It is based upon a three-stage process of mediation, grievance hearing and appeal.

"The process conforms to relevant employment law, ACAS guidance and HR best practice and is added as a schedule to the contract of employment."

The code of conduct has been leaked to the BBC. It says employees have the right to:

be treated with dignity, respect and courtesy by their employer, colleagues, House staff, contractors, visitors and members of the public;

be valued for the work that they do;

be free from any form of discrimination, victimisation, harassment or bullying;

work in an environment free from unwelcome behaviour and inappropriate language.

MPs were expected to:

interact with their employees in a fair, reasonable and consistent manner;

use appropriate channels should issues relating to delivery standards arise;

fully co-operate with the Conservative Pastoral Care Team (CPCT) should a grievance procedure be instigated;

ensure their employees act in accordance with the spirit and ethos of this policy in their dealings with House staff;

lead by example to encourage and foster an atmosphere of respect and tolerance;

not use their position to bully, abuse or harass employees or assume a threatening or intimidating style or discriminate against them.

Labour said that its MPs had a "long-standing complaints procedure in its rules and has never tolerated unacceptable behaviour".

But it is nonetheless in the process of establishing "an independent complaints process which will apply to every member of the Parliamentary Labour Party", a spokesperson added.

"These changes will make sure there is a clear, independent process for people who work for MPs to make a complaint about serious allegations of inappropriate behaviour.

"These proposals have been drafted in conjunction with lawyers, HR professionals and trade unions who represent the staff of many MPs and peers."

'Self-employed'

Commons speaker John Bercow is planning to launch a confidential hotline for MPs or staff who feel they have been the victim of bullying or harassment.

In a statement, Mr Bercow said bullying and harassment in the workplace was "completely unacceptable" and that he would now look into whether procedures in Parliament were in need of reform.

"People are entitled to be treated with dignity and respect as they carry out their work," he said.

"The experience of working in Parliament for an MP should be positive and fulfilling. Time and again, people have told me how fortunate they feel to work here.

"That said, having learned for the first time this afternoon of these allegations, I will consider if there are lessons for the House of Commons to learn or procedures to be reformed.

"MPs are self-employed and employ their staff directly. The House, therefore, is limited in its ability to intervene in cases in which allegations of bullying or harassment by MPs of their staff are concerned. These cases are clearly a matter for the political parties."

Emma Grossmith, senior solicitor at legal firm Just Employment Law, said that some MPs were likely to be "first-time employers", who "may not always have been as robust in their employment practices as they ought".

She added: "It is certainly prudent for the Conservative Party to articulate its expectations.

"But this alone will not be enough to protect MPs from claims. Proper training for both employers and staff is the only way to ensure a permanent culture change."