It may be cold outside but things are hotting up at Marks & Spencer, as Women's Editor Christen Pears finds out.

IT'S hot and humid at the Marks & Spencer spring/summer fashion launch. The gallery where it's taking place has been transformed into a tropical paradise, complete with palm trees and models wandering around in bikinis and sarongs.

Sonja Nuttall is wearing a coat and a furry waistcoat. The designer has just flown over to London from her home in New York and she's feeling jet-lagged and cold.

Sonja is one of the designers behind the M&S Autograph range. Along with Betty Jackson, Anthony Symonds, Orla Kiely and Philip Treacy, she is helping to bring designer clothes and accessories to the high street.

"Autograph has been going for a couple of years now and it's been a huge success. It's a wonderful place to be and I'm quite honoured that I have the opportunity to do it," says the 36-year-old.

She's passionate about the Autograph range, which she believes enables women to buy couture at affordable prices. "I do hope people realise that the designers are totally behind it. We're involved at every stage. We'll say whether the fabric isn't right or whether it needs to be cut differently. It really is the couture approach and I hope the customers feel that when they put the clothes on.

"But Autograph is just one part of what Marks & Spencer are doing. It's not fuddy duddy any more. The M&S customer is the same as any other customer and I don't think about them specifically when I'm designing. I just think about what women want."

Sonja is renowned for her tailoring, and this season's collection includes soft, striped trouser suits and sophisticated prints. "I wanted to make the suit more elegant, less restrictive. I wanted it to be softer, I want women to feel comfortable," she says.

Also in the Autograph range are Betty Jackson's broderie anglaise and denim pieces and Anthony Symonds' flower prints and classic black trenchcoat. Many of the themes from the designers' main collections are carried through into Autograph swimwear.

Elsewhere, in the main collections, M&S has looked to Asia for inspiration. The Bombay Sapphire range is a riot of colour, from hot reds and pinks to oranges. Gold sari embroidery, beaten brass jewellery and eastern prints complete the look.

Other parts of the collection have a colonial theme, with safari jackets, camp shirts, long riding skirts and jackets with Mao-collars. Colours are khaki and neutral and fabrics range from linen and suede to soft chiffons, cut on the bias. The Latino range, with its mixture of bold red and black, offers a complete contrast. Frills, lace and polka dots all combine to give a sexy, retro look.

There are clothes to cater for the older, traditional M&S shoppers, as well as younger customers. The collection includes trendy cargo pants and hooded tops, as well as what will be one of the season's key pieces - the parka. Available in a selection of colours and fabrics, including silk, the 70s favourite has been reinvented for the 21st century.

The popular View From sports range has been expanded to include a specialist yoga section, while there is also glamour sportswear for those who are less keen on exercising than looking good.

Lingerie continues to go from strength to strength with designer ranges from Salon Rose and Collette Dinnigan. The company has been experimenting with fabrics, using the latest technology to make underwear as comfortable as possible. The new Smoothline Nude range caters for every skin tone and is perfect for wearing underneath the season's sheer clothes.

One of the most impressive things about the spring/summer collection is the attention to detail. From tiny bows on bra straps to embroidery on skirt hems, everything is beautifully finished. There are also hundreds of pieces that can be mixed and matched to create your own distinctive look.

The new range is more of the work of M&S creative director Yasmin Yusuf, whose team has helped inject new life into womenswear since she joined from Warehouse.

Her efforts are clearly paying off. Marks & Spencer recently reported a surge of nearly 30 per cent in half-year profits to £287 million, thanks to strong performances in its clothing, home and food departments.