Emily Thornberry says she’s the “street fighter” Labour needs to beat Boris Johnson – but accepts Britain leaving the European Union is now a foregone conclusion.

The Islington South and Finsbury MP last week announced her desire to succeed Jeremy Corbyn as Labour leader and she will compete in a leadership contest in the new year.

The shadow foreign secretary held her seat of 15 years at the polls on December 12 with 26,897 votes, but the Tories smashed Labour nationally to earn a sizeable 78-seat commons majority.

She told the Gazette: "I'm really grateful to everybody in Islington for their support and it's a huge honour to be re-elected as MP - but I'm devastated at the results nationally."

Following the election, Islington North veteran Jeremy Corbyn announced he'll step down as leader once a replacement is elected in the Spring.

She added: "The truth is I hoped we would win the election and Jeremy would be the PM, but that's not happened. I want to make sure this never happens again and we win the next election and, for that reason, I'm standing."

Ms Thornberry says she's "good at the dispatch box" and "got the better" of Johnson in parliamentary debates when she shadowed him as foreign secretary.

The MP says there is "nothing" she disagrees with in Labour's manifesto, but argues the party needs to better communicate what its policies mean.

"I'm strategic and experienced," she said. "I have shadowed seven front bench jobs during my time in parliament. [...] I think it's about time we had a woman as leader. I think it's ridiculous to go through another leadership election and come out with a man."

Ms Thornberry has been an outspoken advocate for a confirmatory Brexit referendum, in which she promised to campaign to remain. But she said: "The truth is we are going to leave at the end of January. I don't think there's anything we can do to stop that. The battle now is to ensure we have a proper ongoing relationship with the European Union."

Asked whether Labour's next leader should be from the north of the country, Ms Thornberry said: "I don't believe Boris Johnson won those seats in the north because he came from the north. And one of our best PMs was Clement Attlee and he represented Limehouse. But you have to have the capacity to represent the whole country."

She added: "The truth is we have five years of hard slog in front of us now. We have to really hold this government to account and make sure they don't get away with nonsense such as announcing 40 new hospitals." In reality, the government has allocated funds to upgrade six hospitals by 2025.