LONDON - That's Kate Middleton? Britain's Royal Mint released a commemorative coin Thursday featuring portraits of Prince William and his bride-to-be, but critics said the results were far from lifelike.

Images of the couple on the memento bear little resemblance to either the prince or his betrothed, who are both 28. Middleton appears plump in the face and lips and has bags under her eyes, while some critics suggested William looks more like former U.S. Vice President Al Gore.

Available in silver or gold, the 5-pound ($7.70) coin - which costs 9.99 pounds ($15.40) to buy - marks the April 29 wedding of the prince, who is second in line to the British throne.

"This coin is of historical importance, to get it so wrong seems ridiculous," Ingrid Seward of Majesty magazine told Britain's Sky News.

The Royal Mint said the coin was designed by its in-house engraving team, and it insisted the portraits had gone through "a rigorous approval process." Both Queen Elizabeth II and William had given their consent to the design, the mint said in a statement, and staff used photos of the engaged couple to produce the images.

Dickie Arbiter, a former royal spokesman, said it was often difficult to produce accurate images on a coin.

Engravers managed a better likeness of William's parents, Prince Charles and Diana, the Princess of Wales, in an official coin released to mark their 1981 wedding. In 2008, the mint released another coin to commemorate Charles' 60th birthday.

"The Royal Mint has been recording historical events for over 1,100 years," said Dave Knight of the mint.

The coin is the latest official merchandise to celebrate the pending royal wedding.