Today a group of MPs aiming to tackle Westminster sex abuse meets for the first time – I'll be there as a critical friend

Later today, a group of MPs convened by the Leader of the House, Andrea Leadsom, will sit down to work on a proposal for a new independent complaints and grievance system in Parliament.

After weeks of horrifying accounts of harassment and abuse in British politics, it’s down to this cross-party working group to put aside political and personal loyalties – and put the interests of those who have suffered harassment or abuse, and those at risk of doing so in the future, at the heart of our work.

As a member of the working group, I’ll be a critical friend and not afraid to call things out. I’m making it my mission push for the boldest action possible in the shortest possible time. We cannot just be a talking shop.

The group is aiming to quickly set up an independent grievance procedure to guarantee that any complaint will be handled properly – and commensurate action will be taken. At the meeting of party leaders last week there was widespread support for improving Parliament’s procedures, and there’s no reason that a new procedure and additional support shouldn’t be in place soon.

Furthermore, such a procedure must cover people both working in Parliament (including contractors) and in our constituencies. That means everyone from our researchers with whom we share offices to the postal workers who deliver mail to the parliamentary estate.

The working group should, of course, be advised by outside experts advocating on behalf of survivors but it must also include experts in preventing violence against women and girls among its membership. Crucially, if we are genuine about this being staff-led, it must include more than just the two staff members currently set to be on in the group.

A ratio of 10 MPs to two staff members isn’t good enough. Nor is using Parliament’s “respect” policy as a basis for new guidelines, as it’s not been designed to deal specifically with allegations of sexual harassment.

A broad bullying and harassment policy is never going to be suitable for the kinds of complaints we know are out there. An effective policy and process will be one that signals to women they will be believed, be in control of who gets to know what and when about them, and seeks to give them back the power that’s taken away when someone is subjected to sexual harassment, abuse or violence.

As part of the proposals, I would also like to see Parliament quickly hire an independent expert to support people who come forward, and offer the support they need if, for example, they aren’t ready or able to go to the police with their complaint. We should also review the way that staff working for MPs are employed – and see if it might be better not to have each MP as an individual employer.

The working group also needs to have a remit that goes beyond just dealing with problems as they arise; it needs to be looking at prevention too. That’s why today I’ll be saying that we should be using this moment to address the toxic culture that runs through Westminster.

That should mean moving forward immediately with training for MPs on appropriate behaviour and consent. At the meeting of party leaders last week, there was agreement that some sort of training would be helpful – I want to see action on this now, and I’d like the working group to investigate how we might dock pay or expenses from MPs who refuse to take part. Perhaps the first MPs to be given such training should be those of us on the working group.

Cultural change doesn’t just mean rooting out illegal and abusive behaviour, which is why I would like this group to see how we might change the way we conduct our politics. To this end, the Speaker must use his powers to suspend MPs from the chamber immediately in certain circumstances. So, for example, if Nicholas Soames ever dares to “woof” at a female MP again, he should be asked to leave the Commons immediately and suspended for a period of time. If Parliament wants to show leadership, then a zero-tolerance approach is what we need.

If the last few weeks have shown us anything, it is that abuse and harassment is not a party political issue – it runs far deeper than that. I hope that, in the weeks to come, we can show that tackling this toxic culture is a mission that transcends party divides too.

If we are united in a commitment to implementing the changes needed to genuinely protect and empower people in the future, and bringing about justice for survivors of harassment and abuse in the past, then we will have done something worthwhile.

Caroline Lucas is co-leader of the Green Party in England and Wales