By the time you are reading this I may have been arrested. Maybe you have already read something about the arrest in the news.

As of now I am sitting safely on the Chiltern Line train heading from London Marlylebone to Moor Street Station.

More than 10 years ago I made up a brand of paint. It was called Drummond’s International Grey. I had 1,000, one litre tins of it made. I was not planning on going into business to compete with Dulux or Crown.

These tins of grey emulsion existed for one purpose only. I was selling them for you to use to paint over anything you found to be morally or aesthetically offensive.

Basically I was in the business of promoting vandalism.

When putting my schedule together for my three months in Birmingham, I planned that I would paint over a big billboard in the city.

I had in mind a billboard advertising one of the big chain of bookies or one for the modern crop of lone shark companies. My prejudices are that these companies prey upon the weaknesses of the weakest in society.

But when I started to work in Birmingham, I was almost disappointed to find there were no current billboard campaigns for these companies, thus nothing to truly offend me.

The lids stayed firmly on my last few tins of Drummond’s International Grey.

That was until last week. As I strolled along Heath Mill Lane towards Eastside Projects, I was confronted with a billboard that offended me in so many ways.

As the train pulled into Moor Street, I was girding my loins for the job that had to be done.

On my return journey the job had been done and as yet I have not been arrested.

Over these past weeks working across Birmingham I have often been asked if what I do is political art. My usual answer is ‘I do not know if it is art let alone political art.’

And when people ask me about my own political leanings, I will usually sidestep the issue by quoting my good friend Zodiac Mindwarp: “I have a right wing, I have a left wing, I am an angel.”

On the right I am for the independent shopkeeper, or the young startup with ambition and on the left I am for the teacher up against the looming Ofsted report or nurse struggling to do their best within the limits of the NHS.

But mostly I’m for politics that are about ideas.

Ideas that are fluid and evolving. What I’m against is politics based on tribalism, be that class, religion or nationalism. And I’m obviously against politics based on dynasty or personalities.

I’m Scottish. I will always want Scotland to beat England at any sport from tiddlywinks on up.

But when it comes to Scottish nationalism in a political sense, I have problems.

I have no idea if Scotland would be better off independent or not. But what I do know is that I want fewer borders in the world not more.

And I don’t want politics that exploit or pander to my more romantic notions of Scotland. I don’t want politics based on a notion of what we think our country once was and may be again.

Artist Bill Drummond modifies a UKIP poster in Birmingham.
Bill before he modified the UKIP poster

Following the same thinking, I have no idea if UK plc would be financially better off in or out of Europe.

But what I most certainly know was yesterday morning I walked past that billboard in Heath Mill Lane that was very cynically trying to pander to us at our most vulnerable and negative and not to our better selves.

I may be in danger of over stating it, but this would have been exactly the same appeal the National Socialist German Workers’ Party would have had in Germany in the years after the First World War when the German people were feeling at their most beaten and vulnerable.

This billboard not only offended me morally and aesthetically it also went against everything that I feel political discourse should be about.

Thus there was nothing for it, after my train pulled into Moor Street, I picked up my last remaining tins of Drummond’s International Grey and got to work.

And just to avoid confusion the word GREY is also my current graffiti tag.

That was only a couple of hours ago, but already the doubts are rushing in.

See all of Bill's articles for the Birmingham Post here

Photos of my handiwork are out there in Facebook and Twitter-land, being shared, retweeted, liked and favoured.

Is all I’ve done pull the pose of the rebel? A mere publicity stunt? Was it done just to appeal to those that would already agree with the sentiments?

By doing this have I added to the political discourse in the country in any sort of positive way? Or does it just entrench opinions? So much of what I perceive to be political art only entrenches opinions.

Or should I be doing the same to every billboard expressing the same sentiments across the West Midlands?

If you have any thoughts on the above maybe you should join me for the knit and natter session between 2pm and 4pm on Saturday at Eastside Projects. I could show you the billboard while we are at it.

• Bill Drummond is writing a weekly column for The Birmingham Post as part of his three-month residency at Eastside Projects, Digbeth.