Penny Mourdant pulled out of the race to be the next British Conservative Party leader
Rishi Sunak will be the new British Prime Minister.
He was elected un-opposed as Conservative leader in the last few minutes.
Chairman of the 1922 Committee Graham Brady confirmed there was just one nomination.
UK Home Secretary Penny Mordaunt dropped out of the race just moments before the 2pm deadline.
Mr Sunak will become the UK's first British Asian Prime Minister, and at 42, the youngest in more than a century.
The Taoiseach has said he'll work with the new British Prime Minister to try and boost relations between the UK and Ireland.
Micheál Martin also called on the DUP to enter the Stormont Executive to avoid new elections in Northern Ireland.
The British Irish Assembly brings together politicians from across Ireland and the UK and is meeting in Cavan today.
None of those present know exactly what British Government they'll be working with by the end of the week.
Least of all Northern Ireland Minister Steve Baker, who might not have a job for much longer, but he believes the wider policy on Northern Ireland won't change.
Taoieach Micheál Martin has called on the called on the DUP to act to avoid fresh elections in Northern Ireland, which could be called on Friday
However, it's widely accepted that won't happen, though DUP reps here have called for ramped up negotiations on the protocol to allow them to get back to work.
Steve Baker says the principle of consent needs to be kept in any deal on the Northern Ireland Protocol, he says everyone must play their part:
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