It could only be... Daniel Day Lincoln

Sporting a Quaker beard, swept-back salt-and-pepper hair and a thin-lipped half-smile, the actor looks uncannily like the 16th US President, despite being on his lunch break.

Seven years in the planning, Spielberg's Lincoln is based on the bestselling book Team of Equals and will focus on the great man's political achievements during the Civil War, when he kept together a cabinet of bitter rivals and succeeded in passing a revolutionary new law abolishing slavery.

Liam Neeson was originally cast in the role of Lincoln, but in 2010 he left the project and Day-Lewis took his place. He's approaching the role with his usual intensity.

Day-Lewis is famous for staying in character during shoots, and a Variety magazine article recently reported that he's been speaking in Abe Lincoln's distinctive high-pitched drawl constantly for months. It's typical of the actor's complete dedication to his craft, and over the years he has gone to extreme lengths to make his acting stand out from the crowd.

He uses the Method technique, invented in the early years of the 20th Century by Russian actor and director Constantin Stanislavski. Method acting encourages actors to create an inner psychological life for characters, and to use emotions from their own lives to make their performances more believable.

The 'Method' became the sacred mantra of 50s stars like Marlon Brando and James Dean, and was lovingly adopted by the generation that followed. Actors like Jack Nicholson and Robert De Niro became famous for staying in character and transforming their physical appearance to be more convincing.

Day-Lewis, though, goes further. His experiments with extreme preparation began on the set of Philip Kaufman's 1988 adaptation of Milan Kundera's The Unbearable Lightness of Being. In order to play Tomas, a sexually promiscuous doctor in 1960s Czechoslovakia, Day-Lewis learnt the rudiments of Czech so that he'd sound like a Czech person speaking English. And he refused to come out of character during the eight-month schedule.

His behaviour during the making of My Left Foot (1989) has become the stuff of legend. He played the lead in Jim Sheridan's biopic of Christy Brown, the Dublin writer and artist who suffered from severe cerebral palsy.

In preparation, Daniel spent time at the Rehab centre in Sandymount studying similar disabilities, and once shooting began he took to a wheelchair and wouldn't come out of it. He spent entire days confined to the chair, his body contorted in imitation of Brown's condition, and sitting so awkwardly that he cracked two ribs.

He taught himself to paint with his foot, spoke at all times in Brown's strangled tones, and had to be spoon-fed and lifted around the set by a not always sympathetic crew. There's even a story about his agent coming over from London to see him during the shoot and leaving in a huff when Day-Lewis refused to emerge from character to talk to him.

His director, though, was understandably pleased. "We never really had conflicts," Sheridan has said. "We had a great rapport. I think he's a poet and probably is one of the greatest."

On Michael Mann's The Last of the Mohicans (1992) he faced a different kind of challenge. To play an 18th-Century Englishman adopted by Mohican warriors, he used rigorous weight-training to add 20lb of muscle to his frame, then took to the woods to learn to live off the land as his character would have done.

He camped in the wild, catching and skinning fish and animals, and carried a rifle with him everywhere -- even, one report has it, to a party.

During filming of Martin Scorsese's The Age of Innocence (1993), Daniel could be seen striding about New York in the garb of an 18th-Century gentleman, including top hat, cape and cane.

On Jim Sheridan's In the Name of the Father, he lived on prison rations to lose 30lb in order to play Gerry Conlon, one of those wrongly convicted of the 1974 Birmingham pub bombings.

He also spent days confined in a jail cell, with crew encouraged to hurl abuse and cold water at him whenever they passed.

And during Sheridan's 1997 drama The Boxer, Day-Lewis was taught how to box by Barry McGuigan, who later said he could have been a professional. "He was in the gym twice a day, seven days a week for nearly three years," McGuigan later said.

Perhaps his most intense performance was as 19th-Century thug and street-fighter Bill 'The Butcher' Cutting in Martin Scorsese's Gangs of New York (2002). Day-Lewis took a butcher apprenticeship and would sharpen his knives on set between takes.

He was diagnosed with pneumonia during the shoot after refusing to wear modern winter coats. And he apparently insisted on referring to co-stars Liam Neeson and Leonardo DiCaprio by their characters' names, and otherwise having little to do with them.

And Daniel has not mellowed with age. While shooting The Ballad of Jack and Rose with his wife, Rebecca Miller, he retreated each night to a shack he'd built on a remote Canadian island, while she and their children stayed in a hotel nearby. And during Paul Thomas Anderson's There Will Be Blood, he slept in a tent on a deserted Texas oilfield to get into the mind of an early 20th-Century oilman.

Co-star Paul Dano spoke of Day-Lewis's terrifying focus during a scene in which his character attacks Dano's. "I got slapped in the face at the start of every take," Dano explained. "Then someone saw the mud, and before long, I'm getting slapped and dragged by the hair, and having Daniel stuff handfuls of mud into my mouth. It's tough in the moment ... "

All of this might sound excessive to the layman, and Day-Lewis has an aversion to talking about his methods himself. But whatever he does, it seems to work. He is gifted and charismatic, comparable to Brando and De Niro in terms of excellence.

He's won two Best Actor Oscars, and received countless other awards and nominations. There's method in his madness, and every film he appears in becomes a major cultural event. Spielberg's Lincoln will be no different.