LONDON-The popularity of Britain’s Prince Charles has taken a dive, according to a survey published on Monday, as the 20th anniversary of Princess Diana’s death approaches.

According to a new YouGov poll commissioned by the Press Association (PA) news agency, only 36 percent of the British public think the heir to the throne has been beneficial to the monarchy. Four years ago, that figure stood at 60 percent.

“We’ve moved on 20 years. Charles’s reputation, I thought, was completely rehabilitated,” royal commentator Penny Junor told PA.

“He gets a hard time because his marriage failed. He’s never been forgiven for that - because Diana blamed him and he never ever said a word,” she added.

Diana’s death in a high-speed car crash in Paris on August 31, 1997, shook the monarchy as the public and the press criticised the royal family for its silence.

Since then, the monarchy’s image has recovered and the once out-of-touch Buckingham Palace press office has overhauled its strategy to focus on distributing positive information.

According to Junor, in the past two decades Charles has become a “much happier, more relaxed and more confident Prince of Wales”.

“And I thought much more popular as a result,” she said.

But Charles has once gain found himself in a negative spotlight in the lead-up to the 20th anniversary of Diana’s death.

To commemorate their mother ahead of the milestone date, Prince William and Prince Harry fronted a documentary on her and commissioned a statue to be erected in Kensington Palace, where she lived for 15 years. But new revelations have surfaced, including tapes showing the late princess of Wales speaking frankly to her voice coach about her loveless marriage to the heir to the British throne and about his affair with Camilla Parker Bowles, now his wife.

Camilla’s popularity has also suffered as only 18 percent of people think she has made a positive contribution to the royal family, down from 28 percent four years ago.

In contrast, William and Harry are seen as having had a positive impact and are credited with 78 percent and 77 percent of positive opinion respectively.

The princes have recently given candid interviews about their struggles following their mother’s death and have stepped up their royal engagements.