Karen Bradley has been sacked as the Northern Secretary by British prime minister Boris Johnson.
Ms Bradley, who was an ally of former prime minister Theresa May, departs her Northern Ireland Office job and Hillsborough Castle residency after 19 months in the post.
Ms Bradley, the 49-year-old MP for Staffordshire Moorlands, was dismissed during a week in which talks were continuing at Stormont aimed at restoring the Northern Executive and Assembly.
“I personally regret that I will not conclude the current talks process,” she said in a statement.
Ms Bradley said it had been “an enormous privilege to represent this special nation and integral part of our precious union”.
Mr Johnson has not yet announced her replacement.
During her period in Northern Ireland, Ms Bradley was unable to persuade the parties to reinstate Stormont, which has been suspended for more than two-and-a-half years.
She was accused of failing to have a strong command of her brief, particularly based on her comments that she was not familiar with the distinction between unionists and nationalists.
She also was criticised for stating that none of the Troubles killings carried out by British soldiers were crimes, a comment she later described as a “slip of the tongue”.
Meanwhile, the Sinn Féin president Mary Lou McDonald said she has written to Mr Johnson seeking a meeting "in the coming days" to discuss Brexit and restoring the Northern Executive and Assembly.
“I have reminded the new prime minister of the requirement of the British government to honour and implement their commitments under the Good Friday and subsequent agreements,” she said. “Agreements that are incompatible with Brexit. The people of the North voted to remain within the EU and that vote must be respected.”
The DUP leader Arlene Foster, in a BBC interview, declined to say whether as part of a continuing supply and confidence arrangement with the Conservative government she would make it a condition that legislation on same sex marriage and abortion should be a matter for a restored Stormont.
Legislation was passed at Westminster this week whereby gay marriage and the liberalisation of abortion law would be introduced in the North if devolution was not restored by October 21st.
She said she was “much more focused” on getting powersharing back so that these issues could be dealt with by the Northern Executive and Assembly.
She hoped that the UK would quit the European Union by the end of October as Mr Johnson has pledged.
However, Ms Foste refused to say that she would use her influence with the Tories to reject a no-deal Brexit, although she hoped there would be a deal with the EU.
SDLP leader Colum Eastwood said Mr Johnson's initial Downing Street address "was bloated with bluff but short on solutions to the challenges of Brexit.
“This new administration, led by a populist, must face reality quickly. Otherwise we’re headed for a no-deal outcome and the interests of Northern Ireland will be sacrificed to sustain Johnson’s grip on power,” he said.
Ulster Unionist Party leader Robin Swann hoped that the optimism in Mr Johnson's speech was "reflected in the actual delivery".
He added: “Rhetoric alone will not solve our problems.”