By Shane Harrison BBC Northern Ireland's Dublin correspondent

Kerry, with its wild mountains, rugged coastline and famous lakes, is undoubtedly one of the prettiest counties in the Republic of Ireland.

It is also the scene of one of the most bitter contests in this year's Irish general election.

Although it is called "The Kingdom", politics in the county are a good deal more republican than royal. And they don't come any more republican than Martin Ferris, Sinn Fein's candidate in North Kerry.

A convicted gunrunner and a former leader of IRA prisoners in the high security Portlaoise prison in the Irish midlands, he is at the centre of allegations of vigilantism.

Martin Ferris: "Attempt to demonise Sinn Fein"

In March, detectives questioned him about the kidnapping of a suspected drug dealer in the county last year.

He was released without charge, but a file on his case has been sent to the Director of Public Prosecutions.

A recent opinion poll in The Kerryman newspaper suggests that rather than hinder his chances of getting elected the controversy has helped him with a sympathy vote. And that's also Martin Ferris's view.

He says the arrest was an attempt to damage him politically.

"The reality is that people have seen it for what it is," he said.

'Colourful past'

"It is an attempt to demonise Sinn Fein and people have responded accordingly."

Fianna Fail candidate Senator Dan Kiely has been highlighting the vigilante allegation in the course of the campaign.

But he, too, is a man with what might euphemistically be called "a colourful past." He has a conviction for bar-room brawling.

He says what he did in the past is very different from what is happening at the moment "with vigilantism and people being taken away in the dark of night and taken into woods and beaten up".

Dan Kiely: Highlighted vigilante allegation

North Kerry is also the political base of Dick Spring, the former Labour leader and deputy prime minister.

He also stresses his opposition to vigilantism but says he is not into negative campaigning.

"There has been vigilantism. Somebody has to be responsible for it. But that's a matter for the Gardai [the Irish police] to carry out their investigations," he said.

On the streets of Tralee, the main town in the county, voters seem prepared to give Mr Ferris the benefit of the doubt while making clear their strong opposition to vigilantism.

That could change if the DPP decides to charge him.

In the meantime, he and the other candidates are continuing to knock on doors enlisting support as they await the peoples' verdict on 17 May.

Kerry, loved by tourists, may be a pretty county but its politics are often uglier than in the rest of the country.

That's hardly surprising this year given the current right royal battle to assume the throne in "The Kingdom".