In his letter to Mr Sunak, published on X on Saturday night, Mr Heaton-Harris said: “Working with you I helped negotiate and deliver the Windsor Framework, which both solved many of the major practical issues created by the Northern Ireland Protocol, put in place as we left the EU, and helped reset our countries’ relationship with our European neighbours.
“Then, after long and detailed negotiations within Northern Ireland, we produced the command paper Safeguarding the Union , externalwhich resulted in the return of Stormont and devolved government to serve the people of Northern Ireland.”
Mr Heaton-Harris added: “I strongly believe the conditions now exist for Northern Ireland to thrive”.
Mr Heaton-Harris, who has been an MP for 14 years, said Northern Ireland had “privileged access for manufactured goods into the EU single market, whilst being an integral part of our UK internal market”
“It finds itself in a remarkable favourable position,” he added.
He added that he wanted to remain as Northern Ireland secretary until the next election as “there are still a number of pieces of unfinished business I wish to complete and I love the people, place and job”.