Boris Johnson promised to “Get Brexit Done” but his successor inherited a bogged-down dispute about special arrangements that were agreed for Northern Ireland.
Liz Truss lasted just 49 days in office, during which time talks with the EU restarted.
Now Rishi Sunak has the keys to 10 Downing Street, he too will face the ongoing row over the Northern Ireland Protocol – part of the post-Brexit deal between the UK and EU.
Mr Johnson’s government introduced a bill in Parliament which could override parts of the protocol – and make it easier for some goods to flow from Great Britain to Northern Ireland.
It was passed by the House of Commons and is currently being debated in the House of Lords.
If passed, the bill would not only affect the UK’s relationship with the EU, but also rules for businesses in Northern Ireland and the future of Northern Ireland’s devolved government at Stormont.
It collapsed in February after the Democratic Unionist Party (DUP) walked out in protest against the protocol, pledging not to return unless its concerns were addressed.
So where does Mr Sunak stand on the protocol?
Mr Sunak has previously been critical of the protocol and garnered recent endorsements from high-profile Brexiteers in the Conservative Party.
However it has also been suggested that he favours a more conciliatory approach than some more hard-line Eurosceptic Tory MPs.
In May, Mr Sunak told Bloomberg the way the protocol was operating was posing enormous challenges to “the stability of the situation” in Northern Ireland.
He said it had become a barrier to re-establishing power sharing at Stormont.
Mr Sunak said the government’s preference was a negotiated settlement and added that he wanted to ensure Northern Ireland’s place in the United Kingdom was secure.
At the end of 2021, the Daily Telegraph reported that Mr Sunak urged Boris Johnson and his former chief Brexit negotiator Lord Frost not to “blow up” talks with the EU about the protocol.
The paper said Mr Sunak raised concerns over the potential impact this would have had on the economy and that he did not have the same sense of “urgency” as others in cabinet about dealing with the protocol.
The Treasury, Mr Sunak’s ministry at the time, declined to comment.
He did not vote on the protocol bill at its second reading but he later voted in favour at its third reading.
After initially backing a return for Boris Johnson, Northern Ireland Secretary Chris Heaton-Harris, a strong supporter of Brexit, supported Mr Sunak’s bid for prime minister, and on Tuesday he was reappointed as secretary of state.
Mr Sunak also garnered the support of prominent Eurosceptic and former chairman of the European Research Group Steve Baker, a junior minister at the Northern Ireland Office before the reshuffle.
Rishi Sunak only made his first visit to Northern Ireland in the summer, attending the Tory leadership hustings at a hotel outside Belfast.
While he spoke briefly about wanting to renegotiate the protocol, there was zero detail during a half-hour Q&A and he has yet to be tested on virtually all policies relating to Northern Ireland.
BBC