Image copyright MATT HOLYOAK/CAMERA PRESS

A new portrait of the Queen and Prince Philip has been released to mark their 70th wedding anniversary.

The royal couple will mark Monday's platinum anniversary with a private dinner with family and friends at Windsor Castle.

The bells of Westminster Abbey, where they married in 1947, will ring to mark the occasion.

Royal Mail has issued a set of six commemorative stamps, featuring the couple's engagement and wedding.

Image copyright EPA Image caption Commemorative stamps from the Royal Mail feature the royal couple's engagement and wedding photos

The Queen and the Duke of Edinburgh are the first royal couple to celebrate their 70th wedding anniversary.

When they married, the then Princess Elizabeth was 21-years-old while her groom, Lieutenant Philip Mountbatten, was 26.

Image copyright PA

Image copyright PA

The new image, by celebrity photographer Matt Holyoak, shows the pair flanked by Thomas Gainsborough's paintings of George III and Queen Charlotte from 1781.

In the photograph, the Queen is wearing a cream day dress designed by Angela Kelly, her personal assistant and dressmaker since 2002.

She also wears a "Scarab" brooch in yellow gold, carved ruby and diamond, designed by Andrew Grima and given to the Queen as a gift in 1966.