UKIP leader Nigel Farage: 'It is time for me to stand aside as leader of this party.'
Nigel Farage has said he intends to stand down as leader of the UK Independence Party to focus on gaining a seat at Westminster.
Mr Farage plans to take on Commons Speaker John Bercow in Buckingham.
He will continue to lead the party's MEPs but said leading the domestic party as well was too much.
"I've also been the leader of the domestic party for the last three years and frankly doing both of those jobs is too much for any one person," he said.
In his three years as leader, Mr Farage has raised the profile of the party, which campaigns for Britain's exit from the EU, through numerous media appearances.
He has also steered it to unprecedented success at the recent European elections, where it came second, beating Labour, and returned 13 MEPs on 17% of the vote.
But he has also faced internal dissent over his leadership style and has found running a UK-based party when he is in Brussels and Strasbourg much of the time too much of a strain.
The South East MEP told his party conference in Southport that he is quitting a year before his term is up in order to focus on winning a seat in the Commons - something the party has struggled to do in the past.
I think I am better to the party doing fewer jobs better
He told delegates: "I do think it is very important that UKIP gets a voice in Westminster."
Explaining his decision to quit, he said: "It is just desperately hard to be leader of a group of people there and to be leader of a domestic political party here. Now that I have decided to fight the Buckingham seat as well, I have come to the conclusion that I may just have bitten off more than I can chew.
"I think I am better to the party doing fewer jobs better."
He said he wanted to continue as an MEP and leading the party in Brussels and Strasbourg, but added: "I simply can not take on the job of planning and executing a national general election campaign on top of all these things."
He told delegates his decision was a sign of the party's success, as it was becoming bigger and winning more seats at local as well as European elections and planning to field 500 candidates at the general election.
"This party has never been in better health than it is now and it is the right time to do this," he said to cheers and loud applause.
The contest to replace Mr Farage as leader is due to get underway next week.
On Thursday Mr Farage said he was standing in Mr Bercow's constituency because MPs "have broken the trust" of the British people and Mr Bercow "represents the worst" of the Commons.
Convention rules that Speakers stay out of party politics. Labour and the Lib Dems will not stand against Mr Bercow.
The BBC is not responsible for the content of external internet sites.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.