Helena Bonham Carter feels ''suffocated by guilt'' when she's away from her kids.

'The Lone Ranger' actress refuses to film on location for more than two weeks at a time because she hates being away from Billy, nine, and five-year-old Nell, her children with director partner Tim Burton.

She told the UK edition of Vogue magazine: ''Since I had Bill that has been the maximum amount of time I've been away. Just long enough to catch up on some sleep but not too long that I miss them and get suffocated by guilt.''

The 47-year-old star splits parenting duties with Tim, 54, who says Helena can be ''insecure'' about being a working mother, but insists it's important for her to strike a balance.

He said: ''Like every mother, she can get insecure about not doing enough or being there enough. But I tell her that work is what feeds a person, that it's important to be creative.''

The 'Les Miserables' star now feels being a parent is her main occupation and doesn't feel pressure to care as much about her acting although, ironically, she feels her acting skills have got better as a result of letting go.

She added: ''It's not my sole purpose so there's less pressure on it, which, of course, means I do it better. But I also find it's less important to me now whether I'm crap or good. I take myself so much less seriously than I used to. I used to be so self-critical it was painful.''