Former social worker and English teacher Paul Gill (38), who lives in Fahan, Co Donegal, claims that making blasphemy a crime undermines freedom of speech.
“It is a draconian, oppressive tool to use against people in a so-called vibrant democracy and it is unenforcable. Laws should be to protect people, not ideals,” he said.
Mr Gill will set out today (Wednesday), from Mizen Head on the 625km trek and will walk 25km a day, sleeping most nights in a tent on the roadside.
He expects to arrive at Ireland's most northerly point of Malin Head in Co Donegal in 25 days’ time.
Along the way there will be public debates and forums for discussion at various venues organised by Atheist Ireland, which is sponsoring the event.
Mr Gill hopes that debate and discussion would encourage the electorate to repeal the law in a referendum later in the year.
The new legislation makes blasphemy a crime punishable with a fine of up to €25,000.
SIC: BT