Working class town Stockton South saw its big Tory majority wiped out by Labour.
Labour's Paul Williams won the seat with 26,102 votes - 888 more than Conservative candidate James Wharton.
- Video report by ITV News Political Correspondent Paul Brand
Theresa May is expected to receive a frosty reception when she meets the 1922 Committee later. But what do we know about the group?
The Prime Minister appointed her former leadership rival as Environment Secretary as she confirms her new top team.
He insisted he would be backing Theresa May as leader and has warned MPs to "calm down and get behind the Prime Minister".