Meryl Streep and Julia Roberts keep it in the family in August: Osage County

Meryl Streep and Julia Roberts seem to have spent much of January in each other's company

Meryl Streep and Julia Roberts lead an all-star cast in the darkly comic family drama August: Osage County. Yet will the Academy show it as much love as its stars have been showing each other?

This year's awards season has seen gurning from Jennifer Lawrence, clowning from Emma Thompson and a series of increasingly outlandish acceptance speeches from Matthew McConaughey.

Yet it has also seen one of the more unlikely red carpet double-acts of recent years: the powerhouse combo of Meryl Streep and Julia Roberts, conjoined in the cause of the strikingly titled August: Osage County.

On screen, the seasoned trophy Hoover and resting queen of the chick flick play Violet and Barbara Weston, a mother and daughter who spend the duration of the film locked in a fierce battle of words and wits.

Off it, however, they have been as pally as sisters, projecting a united front on behalf of a film whose characters, despite belonging to the same extended family, are definitely anything but.

Streep and Roberts play mother and oldest daughter

Based on a Tony and Pulitzer-winning stage play by the (male) playwright Tracy Letts, the film - directed by John Wells - is a caustic comedy of manners full of bilious one-liners, dramatic revelations and withering put-downs.

Surprisingly, though, the central role of Violet, the domineering, pill-popping matriarch of the film's warring Oklahoma clan, was not one Streep initially found appealing.

"I just didn't want to do it," admits the 64-year-old star of Out of Africa, Mamma Mia! and The Iron Lady. "I said, 'I know it's a great part but I just don't want to be her.'

"But they sent me the script and it was so funny and so scathing and so grounded in real pain I thought, 'oh, come on'," she told BBC Radio 2's Arts Show.

The wisdom of Streep's decision was borne out last week when she was shortlisted for the best actress Oscar - the 18th such nomination of her distinguished career.

Roberts was also recognised with her own nomination, in the supporting actress category, for her portrayal of Barbara, Violet's strong-willed, battle-hardened eldest. The 46-year-old is also up for the Bafta equivalent.

Accordingly to Wells, though, any one of his star-studded cast - a stellar ensemble that includes six previous Oscar winners or nominees - could have been legitimately garlanded with honours.

"I don't want to sound immodest but I don't think there's a weak performance," he told the BBC News website.

"There are a lot of very experienced and talented actors in the cast and any number of the performances could be singled out for being wonderful."

That will be music to the ears of actress Juliette Lewis, who put her music career on hold to play the role of Violet's youngest daughter Karen.

The 40-year-old - Oscar-nominated herself in 1992 for her work in Cape Fear - says shooting the film was "a rich experience" she will "treasure forever".

Lewis plays Karen, the youngest daughter in the Weston family

"We all felt like a team together," she says of a cast whose male contingent includes Ewan McGregor and Benedict Cumberbatch. "I'm so proud of the movie and honoured to be a part of it."

Her sentiments are echoed by 17-year-old Abigail Breslin, who says the experience was "mind-blowing" and that "the whole package was perfect".

"It's really just a movie about how you can't pick your family," the Little Miss Sunshine actress says..

"It's really dark and heavy but it's also very funny which is really true to life. The most ridiculous things come out of tragedy sometimes."

For all the enthusiasm of its stars and director, August: Osage County has so far been something of an also-ran in this year's very competitive awards race.

The film walked away empty-handed from the Golden Globe and Screen Actors Guild awards and has posed little challenge to the more feted likes of Gravity, 12 Years a Slave and American Hustle.

The film was unveiled with some fanfare at last year's Toronto Film Festival, a popular launching pad for pictures hopeful of awards consideration.

But it was greeted with respectful rather than ecstatic reviews, with one critic calling it "a bit of a mess" and another suggesting it had failed to "shed its inherent theatricality".

Cumberbatch, pictured with Chris Cooper (l), plays a nephew with a secret

One of the main bones of contention has been the film's ending, which seeks to temper the play's bleak resolution with a hint of optimism.

Wells admits the ending - criticised by some fans of the original stage play - was a thorny sticking point, saying he went "back and forth" on which option to use.

"We tried it one way, we tried it another and then we came back to how it was in the beginning," he explained during a promotional visit to London in December.

One thing that was never altered was the film's title. At times, though, the director - best known for writing and producing such acclaimed US TV shows as ER and The West Wing - admits he was tempted.

Ewan McGregor and Abigail Breslin also have roles in John Wells' film

"You'd never put out a movie with this title intentionally," he says with a grin.

"If it hadn't been a Pulitzer-winning play we would have changed it in a second."

How August fares in the ceremonies to come will not trouble Breslin unduly, who says she is more concerned about how the film is received beyond the red carpet.

"Obviously that's all very exciting, but what's really cool to me is when I get a tweet from someone saying the movie really helped them or reminded them of their family," she explains.

"I like that people are connecting to it. Stuff like that really makes me happy."

August: Osage County is out in the UK and Ireland on 24 January. The Bafta Film Awards are on 16 February and the Academy Awards are on 2 March.

This article contains quotes from an interview with Meryl Streep that can be heard in full on The Radio 2 Arts Show on Friday at 22:00 GMT.