A good upstart: Feargal Sharkey talks protesting, polls and border smuggling

Feargal Sharkey was the frontman of The Undertones - the punk band formed in Londonderry in the 1970s

Even before he had a chance to get his teenage kicks, Feargal Sharkey was out on the streets campaigning.

In recent years, the voice of the former The Undertones frontman has become almost as well known for protest as music.

He has spoken out passionately about the effects of pollution on rivers in the UK and been a loud advocate for the music industry.

With a trade unionist father and an activist mother, it was probably inevitable that campaigning would end up in his blood.

Feargal Sharkey - before The Undertones

"Both were very actively involved in the civil rights movement," he told the BBC's Borderland podcast.

"In fact there are allegations - albeit it is true - that my father and his friends smuggled a transmitter across the border that became the epicentre of Radio Free Derry.

"I grew up in a household where politics, electioneering, campaigning, driving debate and discussion was just an everyday event."

At a young age he was dragged into all of that, in both a metaphorical and physical sense.

At one stage in the late 1960s, his mother piled all of their family into a car and drove them from Londonderry to Drogheda to take part in the people's democracy march.

"I was 10 years old, walking down the middle of the main road between Belfast and Dublin, waving very enthusiastically what I later learned was an anarchist flag."

Well over five decades later, Sharkey is still a very visible and effective campaigner.

The Undertones were formed by a group of friends during the Troubles

He said it was likely he would lend his voice to the campaign for a united Ireland, if a border poll was held.

"I probably would and again it just goes back to my historical roots," he said.

"I think it's extraordinary that in my lifetime, we're even having this conversation and with any seriousness.

"Because let's face it, until Brexit, this was nothing more than a kind of an ambition that some people had and others didn't share.

"For me, I think it's inevitable now that at some point in the future, there probably will be a united Ireland."

'Allowed to have his dreams'

He was speaking on the latest edition of Borderland - UK or United Ireland? which focuses on campaigning.

It looks at what lessons can be learned by both sides of the unity debate from previous referenda, including votes on the Good Friday Agreement, Scottish independence and Brexit.

On the programme, former DUP MP Ian Paisley dismisses Sharkey's belief that a referendum would lead to a united Ireland.

"Feargal is allowed to have his dreams and he's entitled to them," he insists.

"I don't think all of the facts line up."

However Sharkey says the political progress made since Northern Ireland's 1998 peace deal makes him optimistic that old divisions can be broken down.

"I stood on national television on the 25th anniversary of the Good Friday Agreement on Have I Got News For You - highlighting what the Belfast Agreement has delivered for the peoples of Ireland over the last 25 years.

"It is unbelievably extraordinary.

"And if that simple fact of what the people of Ireland - and particularly the people of Northern Ireland - have achieved in the last 25 years, does not give us hope and prosperity for the next 25, I don't know what better lesson you need."

The latest edition of Borderland - UK or United Ireland? is available now on BBC Sounds and from all main podcast providers.