Back for her third turn as Helen Fielding’s irrepressible Bridget Jones, Renée Zellweger proves as funny and endearing as ever.

She has a new predicament to wrestle with in her inimitably cack-handed fashion: pregnancy. But is the prospective dad Patrick Dempsey’s billionaire American Jack, following a bonk in a music festival yurt, or Colin Firth’s uptight Mark Darcy, courtesy of the briefest of rebound flings a few days later?

It’s a slender plot, but original 2001 film director Sharon Maguire, returning to the helm after sitting out the weaker 2004 sequel, makes the most of the gags in a screenplay co-written by Fielding, Dan Mazer and Emma Thompson.

The rivalry between Dempsey’s smooth Yank and Firth’s ill-at-ease Englishman produces some sniggers, Thompson provides her share of giggles as Bridget’s droll gynaecologist and Sarah Solemani supplies rude chuckles as a brazenly sassy TV newsreader.

But it’s Zellweger who induces the film’s biggest, heartiest, most joyfully good-natured guffaws.