Cliff Claven's going to be jealous.

The U.K.'s favorite letter carrier -- that's postie in Britain -- is coming to the big screen.

Postman Pat's first feature, You Know You're the One, will be released in the spring of 2012 -- the animated postman's 30th birthday -- Classic Media and RGH Entertainment announced Friday.

Stephen Mangan (Episodes, Green Wing, Dirk Gently) will provide the voice of the postman. Jim Broadbent (Iris, Moulin Rouge!), Rupert Grint (Harry Potter) and David Tennant (Doctor Who, Harry Potter and the Goblet of Fire) also lend their voices.

In the 3D movie, Pat encounters the temptations of money, status and a shiny new suit when he enters a national TV talent show competition that threatens to tear him away from his hometown of Greendale and the friends he loves. What happens when kindness meets selfishness? When local fame meets global notoriety? A nice cup of tea is kicked aside by a frappacappucino? Pat is set to find out as he falls for the age-old temptation of the grass being greener.

Postman Pat is a big deal in Britain.

He's an iconic British hero, Mangan said in a written statement. When I excitedly told my 3-year-old son that I was going to be Postman Pat, he said, 'No you're not, Dad, don't be silly.'

A favorite of the UK's preschoolers, the character stars -- as much as an animated letter carrier can star -- in the television series Postman Pat Special Delivery Service, in which he uses his helicopter to deliver anything, anytime, anywhere, according to RGH. The show airs on CBeebies in the UK and in more than 80 other territories.

Perhaps most important, Postman Pat is a top 10 preschool toy property in the UK.

Kim Fuller (Spice World, High Heels & Low Lifes) and Annika Bluhm, the producer of the Postman Pat television series, wrote the script. Mike Disa (Hoodwinked Too!) is directing.

The movie begins production this month.