Cannes will roll out the red carpet on Wednesday for the start of the world's biggest movie festival, with a line-up of directorial big guns poised to go head-to-head in a year of comebacks, swansongs and star debuts. Heavyweights David Cronenberg, the Dardenne brothers, Jean-Luc Godard, Mike Leigh and Ken Loach are among the film-makers who will battle it out for the top Palme d'Or prize at the 67th Cannes Film Festival. Launching the 12-day movie extravaganza with a blast of controversy will be the premiere of "Grace of Monaco", the keenly awaited biopic in which Nicole Kidman stars as the former Hollywood actress Grace Kelly. Already embroiled in not just one but two rows, the film has become a high stakes affair for French director Olivier Dahan who has taken on both Grace's princely family, the Grimaldis, and US distributor Harvey Weinstein in pursuit of his cinematic vision. Dahan and Weinstein have been locked in a dispute for months over what the Frenchman has called Weinstein's "catastrophic" alternative version of the film. Dahan's edit will be the one shown at Cannes but reports say Oscar-focused Weinstein is still not happy and wants more scenes for US audiences covering the actress's time in Hollywood. Grace's children, who are not expected at the premiere, have denounced the film's trailer as a "farce" and accused its makers of hijacking their family history for commercial purposes. High stakes premiere There will, however, be no shortage of star-wattage with Meryl Streep, John Cusack, Robert Pattinson, Juliette Binoche, Tim Roth and Kristen Stewart among the red carpet possibles. Double Oscar winner Sophia Loren, 79, one of the last great sex symbols of the 1950s and 1960s, will supply some old-school glamour when she attends an out-of-competition screening of her latest film "The Human Voice". All eyes will also be on debuts by Canadians Ryan Gosling and Xavier Dolan. Gosling's "Lost River" -- in the new talent Un Certain Regard section -- will test if the 33-year-old "Drive" star can make the transition from leading man to director. And wonderkid Dolan -- who at 25 has already had three films screened at Cannes -- will make his debut in competition with "Mommy". Eighteen films will be in the running for this year's Palme d'Or with New Zealand director Jane Campion heading the festival jury. Famed for its winning combination of French Riviera glitz and arthouse gravitas, the festival prides itself on discovering the movie world "auteurs" of tomorrow such as Steven Soderbergh and Quentin Tarantino. Festival organisers select only a fraction of the 1,700 films submitted each year to compete for the top prize, with a competition slot at Cannes considered one of the greatest honours that can be bestowed on a director. It will be the end of an era if as expected Loach's "Jimmy's Hall" turns out to be his final feature film before he gives up the director's chair to concentrate on documentaries. The British veteran film-maker and Cannes regular, 77, who made his name with "Up the Junction" (1965), "Cathy Come Home" (1966) and "Kes" (1970), won the Palme d'Or in 2006 for "The Wind that Shakes the Barley". Glitz and gravitas Others for whom this year could be their last Cannes outing include French "New Wave" director Jean-Luc Godard, now 83. Festival chief Thierry Fremaux admits it is anyone's guess whether the Swiss Godard will turn up for the screening of his 3D film "Adieu au Langage". He skipped the premiere of his movie "Socialism" in 2010, mysteriously blaming "problems of the Greek kind". "He has promised to be there, which doesn't mean anything of course," Fremaux joked last month. A more low key US presence for 2014 comes in the form of Tommy Lee Jones' western "The Homesman", recommended to Fremaux by last year's head of the jury Steven Spielberg. The film marks the "Men in Black" actor's first return to the competition since he brought "The Three Burials of Melquiades Estrada" to the Croisette in 2005. Also back in competition are Belgium's Jean-Pierre and Luc Dardenne with "Two Days, One Night"; a win for the brothers would make them the first film-makers to lift the Palme d'Or for a third time. John Boorman's "Queen and Country", being screened out of competition in the Directors' Fortnight, will be a festival highlight. The British director's sequel to his hugely popular 1987 film "Hope and Glory" comes more than a quarter of a century after that film picked up five Oscar nominations. Asia and Africa, meanwhile, will be represented in the main competition this year by Japan's Naomi Kawase with "Still the Water" and Abderrahmane Sissako from Mauritania with "Timbuktu".