Monarchists often argue that the without the monarchy the UK would be doomed. Either our tourism industry would collapse, we'd suffer political instability, or our national identity would disappear.
In the first half of the 20th Century one part of the UK did become a republic - Ireland. It gained its independence from the UK and replaced the monarch with an elected head of state.
Far from the ridiculous claims of the monarchists, Ireland has prospered. Its economic growth puts Britain to shame.
The Irish have not lost their national pride or identity - instead they've managed to export their culture and brands around the world.
Ireland has not ended up as a dictatorship - it is a healthy democracy.
Tourism to Ireland has boomed, despite the rather wet climate. And it has managed to shake of its role as a largely agricultural part of the UK to become a forward-looking high tech economy, attracting companies like Dell and Google.
More recently, the Economist decided that Ireland was the best place in the world to live.
Monarchists make many ridiculous claims about how our society, culture and prosperity will suffer as a republic, but this is not supported by the facts - the only part of the UK to have become a democratic republic has prospered.
BBC News - Ireland is named 'best country'