...because she doesn’t want to be seen as William’s official stand-in

Invitation: Kate Middleton turned down an offer from the Queen to host a table at Royal Ascot

Kate Middleton has turned down a personal invitation from the Queen to host a table at Royal Ascot this week.

Prince William’s 26-year-old girlfriend has said she ‘doesn’t want to be standing in for Prince William again and using her Royal status’.

Last month she represented William at Peter Phillips’s wedding at Windsor Castle while the Prince was in Africa.

Miss Middleton was personally invited by the Queen to host a table for ten friends at the private hospitality tent in the Royal Enclosure this Thursday.

Although Kate, a keen horse racing fan, may well still attend the world-famous sporting event, she has told friends she will not take up the offer to host a complimentary table courtesy of the Queen.

A friend of the Middleton family said yesterday: ‘Kate was all set to take the table after having been personally invited by the Queen. She then had second thoughts and politely declined the offer.

‘Princes William and Harry were both invited to Ascot, but neither of them can go, and so Kate was invited to take William’s table.

‘She loves the races and would have so enjoyed to host her own table, but she said she doesn’t want to be standing in for William again and using her so-called Royal status.

‘She knows that if she goes in William’s place as a guest of the Queen the engagement rumours will gather momentum and it’s not what she or William want.’

The source added: ‘Kate’s also been advised to take a back seat publicity-wise, so she’ll only really step out in any sort of Royal capacity when she absolutely has to and when she’s with William.

‘She stood in for William at Peter Phillips’s wedding because he asked her to, but Kate is wary of being seen as William’s official stand-in.’

No thanks: Kate Middleton politely declined the Queen's invitation to host a table at Royal Ascot because she is wary of being seen as William's official stand-in

The Queen has invited her granddaughters Princesses Beatrice and Eugenie who will each host tables of ten on Friday. Zara Phillips was also invited to have her own table on Ladies’ Day but is also understood to have pulled out.

Prince and Princess Michael of Kent’s children Lord Freddie and Lady Gabriella Windsor have been given tables to host on Saturday.

A Royal aide said: ‘The Queen is very keen for the young Royals to get into racing as it is her favourite pastime and lots of her horses compete at Ascot.

‘This year, to encourage her grandchildren to get into the sport, she invited them each to have a complimentary table. Kate Middleton was also invited, but she has turned down the offer.

The Queen will be hosting her own table on Tuesday and will attend the races every day.

‘Guests are invited for drinks, followed by a walkaround then lunch. After that it’s the races followed by afternoon tea. It’s a lovely day out.’

Buckingham Palace declined to comment on who had been invited to the Royal Enclosure.

A spokesman said: ‘We only ever discuss the formal part of Ascot. Everything else the Queen does is private and personal.’