Do we need a head of state? Yes, absolutely. The job of head of state is important and it needs to be done by someone who is genuinely independent of the government and above day-to-day party politics. That can't be the Queen, because all she can do is what she's told by the Prime Minister. And it can't be the Speaker of the House of Commons either, because he's already got an important job, but one that's not independent of MPs.

Most of us are so used to the Queen as head of state that we often assume the way she carries out the role is the only way it can be – or should be – done. So people often ask, as she doesn't do much why not just get rid of the role altogether? Yet an effective head of state – one that’s separate and independent from the government and MPs - can play an important role in a parliamentary democracy.

In a parliamentary system, it is parliament that should have the last word in what laws are passed, not the government (at the moment MPs usually give the government what they want). But even parliament should have clear boundaries and limits on what it can and can’t do. Limits would protect the rights of ordinary people and ensure politicians can’t change the rules to suit their own interests.

So we can share power between the people, parliament and government by limiting the powers of the politicians in a written constitution. The head of state would then have the job of signing into law any Bill passed by MPs – and they could refuse to sign it if they believe the Bill is not allowed under the constitution (but not because they disagree with it).

A head of state can also play an important role at times of political crisis - if we get another hung parliament, for instance, or a prime ministerial resignation. When there’s a long period of political uncertainty and instability, the head of state can play a role in facilitating the formation of a new government or reassuring the nation.

So the point of the head of state is to be a kind of referee in the political system, defending the constitution and working to bring sides together in the interests of the country. That person needs to be independent of parliament and government, as well as accountable for their actions.

Aside from these limited powers, the head of state would represent our country on the world stage and take a leading role at times of national celebration, uncertainty or tragedy. In carrying out these parts of the job, an elected head of state knows they will be held to account for their words and actions, providing a strong incentive to be unifying and inclusive.

We can see these kinds of heads of state in Ireland, where men and women such as Michael D Higgins, Mary Robinson and Mary McAleese have served with distinction and huge popular support.

If a president attempts to overreach their powers, there would be a clear process for removing them from office - unlike with a monarch. And an elected head of state would be paid a straightforward annual salary, with a small office and one official residence; the public would not fund their extended family or maintain multiple homes.

We support a parliamentary system, but not the way it works at the moment. We want to take what we have now – parliament, government and head of state – and make the system democratic from top to bottom. With a head of state who can play a real role as defender of the constitution and representative of the country and nation.