The announcement comes after Ms Foster attempted to play down an attempt to oust her amid reports that a significant number of elected DUP representatives – both at Westminster and Stormont – had signed a no-confidence motion.
“Stories on leadership come up from time to time, and it’s one of those times,” she insisted on Tuesday evening.
However, in a statement published 24 hours later, Ms Foster, who has led the party for over five years, announced her imminent resignation, saying it had been the “privilege of her life” to represent the people of Northern Ireland.
“A short time ago I called the party chair (Lord Morrow) to inform him that I intend to step down as leader of the Democratic Unionist Party on 28 May and as first minister of Northern Ireland at the end of June,” she said.
“It is important to give space over the next few weeks for the party officers to make arrangements for the election of a new leader. When elected I will work with the new leader on transition arrangements.”
Indicating her decision will mark the end of her political career, she said she was preparing to “depart the political stage”.
Ms Foster added she had “sought to lead the party and Northern Ireland away from division and toward a better path”, adding: “It is my view that if Northern Ireland is to prosper then it will only do so built on the foundations of successful and durable devolution.
“That will require continued hard work and real determination and courage on all sides.”
In recent weeks, the party led by Ms Foster has faced growing anger from the unionist community over its handling of Brexit, with the implications of Boris Johnson’s Brexit deal becoming clear.
Critics have accused the departing DUP leader of not being vociferous enough in opposition to the Northern Ireland Protocol, which governs the new trading barriers between Northern Ireland and Great Britain.
But in a parting shot at the UK government, Ms Foster added that the protocol – a key element of the Brexit agreement – had been “foisted upon Northern Ireland against the will of unionists [and] has served to destabilise” the country.
There has also been controversy of her recent decision to abstain in a vote on banning gay conversion therapy – a discredited practice that seeks to suppress or change an individual’s sexual orientation.
In response to her resignation, the Northern Ireland secretary Brandon Lewis described Ms Foster as a “truly dedicated public servant”, adding: “There are many young people, particularly young women, who will be inspired by her example to follow a path into politics.
“I wish her all the best and look forward to continuing to work with her in the days and weeks ahead, delivering all for the people of Northern Ireland.”
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