A Teesside Labour MP has cited "irreconcilable differences" with the party's leadership for his decision not to stand in the general election.
Tom Blenkinsop has been MP for Middlesbrough South and East Cleveland since 2010.
Prime Minister Theresa May announced she wants to call an election 8 June. A Commons vote will be held on Wednesday.
Mr Blenkinsop said he has "made no secret" of his differences with Labour leader Jeremy Corbyn.
Mr Blenkinsop said: "It is because of these differences I feel I cannot in good faith stand.
"Representing the people of Middlesbrough South and East Cleveland has been the proudest years of my life.
"I will do all I can in my time remaining as an MP to champion my constituents and the area that means so much to me, as I have been proud to do over the last seven years."
Labour Bishop Auckland MP Helen Goodman told BBC Tees she had "no idea" if other MPs would follow his example but she was sorry to hear he was leaving.