While fans in London are jiggling around in their pants with exhilaration over her arrival next month, staff at London's fi ve-star hotel The Dorchester are having a hernia over her diva demands.

The 27-year-old warbler announced to bewildered employees that she will only consider staying in their lavish dwelling if she is given a room that has "NEVER" been smoked in.

The barmy pop tart's other requests included humidifiers in all areas, plus a selection of the latest magazines - including her favourite, OK!

Then there's a fresh selection of fl owers that she will arrange herself, DVDs of her much-loved Marilyn Monroe movies, books - ideally chick lit novels - and lighting provided via 100 watt bulbs.

So no low lighting, guys.

A source tells us: "Britney may only be staying in the city for two weeks but she knows exactly what she wants and needs if she is to be happy.

"She'll be bringing all her own pillows for ultra comfort and her security will sleep outside her suite every night." And the Womanizer singer's rider didn't end there.

She also requested running routes in the nearby Hyde Park, horse-riding opportunities and tickets for various West End shows.

And she also insisted on a list of several different routes to the O2 Arena from the hotel - after all, a gal has gotta keep those crazy fans and paparazzi at bay.

Our source continued: "Britney is also hoping to make a private visit to Kensington Palace.

"She has also decided she will travel by private plane to Manchester for her MEN gig - then fl y straight back to London."

Brit's Circus is only in Blighty for an eight-show stay - so what the hell would she need for a more permanent visit? Crazy pop star?