LONDON – She’s a double Oscar winner with a knack for accents, but Meryl Streep says playing Margaret Thatcher was a challenge – although her own experience helped her understand the struggles faced by Britain’s first female prime minister.

Streep is transformed into the divisive politician who reshaped Britain in “The Iron Lady,” which opens today.

“It was extremely daunting, because I’m from New Jersey,” Streep said in an interview ahead of the movie’s London premiere this month. “And yet as an outsider, I felt something of what she might have felt.”

Streep, who won Academy Awards for “Kramer Vs. Kramer” and “Sophie’s Choice,” said her youthful experience as one of a handful of women at Dartmouth College in New Hampshire helped her understand Thatcher’s isolation. In 1970, Streep spent a term as an exchange student at the men-only college, which became coeducational in 1972.

“There were 60 of us and 6,000 men, and I had a little flashback to that moment,” Streep said. “And so a little bit of my emotional work was done for me.”

Streep, 62, has been nominated for a Golden Globe and looks likely to get a 17th Oscar nomination for her spookily accurate performance as Thatcher, who led Britain from 1979 until 1990.

As prime minister, Thatcher fought a war with Argentina over the Falkland Islands, saw the 1989 fall of the Berlin Wall and the implosion of communism.

She was branded the Iron Lady by Soviet journalists for her steely resolve.

She presided over the decline of Britain’s industrial might and trade union power and the birth of a free-market culture with new winners and many new losers.

That historical drama is only glimpsed in “The Iron Lady,” which depicts the now 86-year-old Thatcher, widowed after the death of husband Denis (Jim Broadbent), looking back on her life as a provincial grocer’s daughter rising to the top of a Conservative Party dominated by wealthy men.

Streep said while the film has been called a political biopic, “I was interested in it precisely because it wasn’t really that.”

“It’s a subjective imagining,” she said. “It’s not the God’s-eye-view chronicling this side, that side, the politics of it. It’s a very deep look at a whole life – from the end of it.”

Streep is fascinated by the venom Thatcher provoked – she’s still either loved or loathed by most Britons – and the film gently asks viewers to consider whether the fact that she is a woman played a part in the strong responses.

“She was called the most hated woman in Britain because of policies that lots of people who are still in the political world helped her construct, and they don’t endure the same hatred,” Streep said.

“She was hated for her hair and her handbag and her clothes and her manner and the fact that she changed her voice.

“It was really outsized, the bloodlust, and that’s interesting.”