The 23 June referendum on Britain's membership of the European Union is a moment that will define the future of our country.
It is a choice not just about our EU membership but our national identity.
Britain itself is on the ballot paper, because a vote to leave the EU will embolden those who seek to break up our United Kingdom. That would be a terrible consequence of Britain leaving the EU.
I say that as someone who is unashamedly patriotic and loves Britain. My frustration though, is that we don't fulfil our potential - that we could do better. Of course we get frustrated with Brussels. Of course the EU needs to be reformed. But leaving is not the answer.
Anyone who truly understands what patriotism means, knows that it is about our shared national identity, our culture and values.
It is not about wrapping yourself in the Union Jack. It's about standing up for our country: doing the right thing for our people.
We should be proud that here in Britain we combine our patriotism as Brits alongside our distinct national patriotic identities of England, Scotland, Wales and Northern Ireland.
So let us be crystal clear that whilst some who want us to leave the EU are already claiming a monopoly on patriotism, there is a deeply patriotic case for Britain remaining in Europe.
Because as a country we have always been at our best when we have been outward looking and confident.
This referendum is a test of our national ambition and the extent to which we want to make a contribution to the world.
Do we continue as a country seeking to play a role on the global stage or do we consign ourselves to a bit-part role of an island in the North Atlantic? Like Iceland but with more daylight hours.
Can anyone really say it is patriotic to put our country in a situation where we would have to beg our European neighbours to access their common market while no longer having a say over the rules?
I think it is patriotic to stay in Europe so that the people living in every corner of Britain can benefit from a stronger economy, better jobs and more protection for their rights at work.
It is patriotic to be part of Europe-wide rules like the European Arrest Warrant that keep our people safe and make sure terrorists and criminals face justice.
And it's patriotic to say that the EU has made a vital contribution to making Western Europe more secure, enjoying its longest period of peace in 2,000 years.
After a scrappy first week-end of campaigning, I want to see an argument for a positive patriotism based on our shared values. That demonstrates beyond doubt that it is in our national interest to remain in a reformed EU.
That says Britain will be a global player instead of pulling up the drawbridge.
The starting gun on this referendum has finally now been fired - it'll no doubt be a long campaign so let us fight it with passion and principle.
But let us also be clear that in this referendum a vote for remaining in Europe is the patriotic choice for Britain.