LONDON (Reuters) - Prime Minister Boris Johnson visited former strongholds of his Labour opponents in northern England on Saturday and pledged to repay their trust for helping to deliver a stunning victory for his Conservative Party in Britain’s national election.

Johnson led the Conservatives on Thursday to their biggest election win since Margaret Thatcher’s landslide victory of 1987, trouncing his socialist Labour Party foe Jeremy Corbyn by capturing 365 parliamentary seats and securing an overall majority of 80. Labour won 203 seats.

The election saw the crumbling of Labour’s “Red Wall” of formerly safe seats in working-class areas across northern and central England where most people voted in a 2016 referendum to leave the European Union.

Johnson, the face of the “Leave” campaign in that referendum, fought the election on the slogan “Get Brexit done”.

“I know that people may have been breaking the voting habits of generations to vote for us,” Johnson told supporters in Sedgefield, a symbolically important seat as it was once held by former prime minister Tony Blair, Labour’s most successful leader.

“I want the people of the northeast to know that we in the Conservative Party, and I, will repay your trust.”

Brexit was widely seen as the decisive factor in the election, with Johnson’s promise to take Britain out of the EU by Jan. 31, 2020, winning over many former Labour voters.

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“What an incredible thing you have done, you have changed the political landscape, you’ve changed the Conservative Party for the better and you’ve changed the future of our country for the better,” said Johnson.

“First of all, what are we going to do to repay that trust? We are going to get Brexit done.”

Johnson, who called the snap election to break years of deadlock in parliament over Brexit, has also promised to spend more money on health, education and the police.

Addressing newly elected Conservative lawmakers, Johnson evoked Blair’s own words on taking office.

“When we get down to Westminster and we begin our work, remember we are not the masters, we are the servants now...and our job is to serve the people of this country and to deliver on our priorities. And our priorities and their priorities are the same,” he said.