Tracey Emin said she gets flashbacks when she is near her famous bed artwork as it is prepared for auction for the first time.

My Bed, which comes complete with empty vodka bottles, cigarette butts and discarded condoms, is being sold at Christie's on Tuesday by millionaire art collector Charles Saatchi.

The controversial piece, which was shortlisted for the Turner Prize in 1999, is expected to fetch between £800,000 and £1.2 million.

Speaking at Christie's in central London, where the bed went on display today, Emin said she still stands by her work which "changed people's perceptions of art".

She said: "This is a surreal experience. Every time I'm near the bed or install the bed I get flashbacks and recollections of when I first saw the bed, which was in my bedroom and that was 16 years ago.

"When I made the bed today, I actually had to get in it and pull the duvet over me and push it back to make it feel real and look real.

"Even the smell and ­everything, it's all still there for me. It's very, very ­evocative. Except it's like waking up - I wouldn't say a nightmare, but definitely it's really strange.

"It's now going on a ­different journey. I just hope it goes to a nice place. It's helped me a lot."

Emin, 50, said reactions to the artwork, varied across the globe.

"In Japan they were shocked by my dirty slippers but they stole some bloody knickers and some condoms," she said.

"In America it was like, 'Yeah, we've seen feminist art before, we've done it already', no fuss, just treated it like a regular artwork.

"In the UK, it just exploded with the Turner Prize. It just went crazy."