Ian Paisley stepped down as First Minister and leader of the DUP in 2008, but continued to represent North Antrim at Stormont and Westminster.
Read Ken Reid's blog: End of an Era
"It became apparent to me some time ago that he was going to step aside", UTV's Political Editor Ken Reid said.
The DUP will officially select its Westminster candidate for the North Antrim seat next week.
"I will have my name in the hat; there's absolutely no doubt about that", Ian Paisley junior told UTV.
"The issue and the decision, I will leave to the wisdom of my North Antrim association and it's up to them to decide who they want to take on the mantle of the Democratic unionist party".
TUV leader Jim Allister has already announced he will be fighting the election in North Antrim, promising to lead a fierce electoral battle in the unionist heartland.
"In the early years Ian Paisley was a very effective, efficient MP and he became a towering parliamentarian and no-one can say otherwise than that", Mr Allister told UTV.
"His legacy latterly in terms of effectiveness in parliament has been so much less (...) missing 82% of the votes in this parliament.
"Politically, his legacy tarnishes his very principled stand for many years because his legacy now is of terrorist inclusive government", Mr Allister added.
Legacy
The founder of the DUP, who will be 84 in April, revealed his intention to retire to Ballymena Guardian Editor Jim Flanagan.
"He has fought 19 elections and won every one of them, so he is obviously well thought of in this town", Mr Flanagan told UTV.
"He has been a huge figure here. There is no doubt about that."
Mr Paisley took the seat from official unionist Henry Clarke in 1970.
"He hadn't intended to stand but according to Ian, Clarke burnt a photograph of him at a public meeting in Kells and that encouraged him to stand. He then overturned a huge majority and has held the seat ever since, fairly comfortably, it has to be said," Mr Flanagan recalled.
Ian Paisley said he entered politics to fight republicanism. But fighting what he called "big house unionism" was also a strong motivating factor.
"He believed that big house unionism people got elected because they were part of the establishment and didn't look out for the working class," Political Commentator Jim Dougal told UTV.
"Throughout his career he has used his powers of oratory to bring people along with him and to vote for him, that's where he got his votes from working-class protestants, eventually to fight against republicanism".
Mr Paisley was also a founding member of the Free Presbyterian Church in Ireland in 1951.
His evangelical theology heavily influenced his political views and throughout the Troubles he forthrightly denounced Catholicism and the papacy.
He was, at first, a fierce critic of power-sharing with nationalists and of the Republic of Ireland having a say in Northern Ireland's affairs.
His decision to accept the position of First Minister alongside Deputy First Minister Martin McGuinness in 2007 saw him hailed as a peacemaker although former followers also accused him of betrayal.
"I believe I showed the leadership required to get the best possible deal in the circumstances," Mr Paisley said.
Reactions:
- Deputy First Minister Martin McGuinness:
"I would make no secret of the fact that myself and Dr Paisley come from very different political backgrounds and for much of his political career I would have strongly opposed much of what he stood for."
"In more recent times however, particularly in the time that we spent in government, I found that we could work together for the good of the people that we represented without compromising our beliefs - he as a unionist and myself as a republican.
"I have to say also that in that time he and I became friends and we remain in contact still and I would wish him and his wife Eileen all the best for the future."
- Prime Minister Gordon Brown:
"He has been a passionate advocate on behalf of the unionist community for over four decades and his courage, both in committing to the path of reconciliation and compromise and in playing such a significant part in bringing the unionist community in Northern Ireland with him, has enabled Northern Ireland to look forward to a bright, peaceful and more prosperous future."
- Northern Ireland Secretary Shaun Woodward:
"He is a remarkable figure whose politics are born from the deepest principles and most fervently held conviction and who not only contributed to debate but often dominated it".
"His decision to share government with Sinn Fein and to work as first minister with Martin McGuiness as deputy first minister sent a beacon of optimism around the world."