Is Pippa Middleton secretly engaged?

Pippa Middleton and her boyfriend, Nico Jackson. There are rumours the couple are engaged.Photo / AP

Pippa Middleton is secretly engaged to her stockbroker boyfriend, Nico Jackson, according to reports.

The couple, who've been dating for six months, will make the announcement after Pippa's 30th birthday party on September 6.

An insider told The Sunday People that the famous bridesmaid and her beau were hiding the news "because they didn't want to take the shine off Kate and her baby."

Pippa's sister Kate recently gave birth to the future King of England, baby George, her first son with husband Prince William.

Image 1 of 15: An easel stands in the forecourt of Buckingham Palace in London to announce the birth of a baby boy, at 4.24pm to the Duke and Duchess of Cambridge at St Mary's Hospital in west London. Photo / AP

A friend of the couple told the paper: "Pippa loved seeing Kate go down the aisle and now it is her turn for a ­fairytale wedding.

"She couldn't be more sure that Nico is the right man for her.

"They are such a good fit for each other and their families get on really well. Everyone is so happy for Pippa."

- www.nzherald.co.nz