This is the heartwarming moment passersby cheered as a woman proposed to her girlfriend in England.

Khai Evangelista, dressed in a black coat, surprised her long-term partner, Claire Gana, with an engagement ring in the middle of the pathway at Windsor Castle.

Footage shows the pair smiling for photos when Khai asked Claire, wearing a grey coat, to turn the other way.

Moments later, Khai lowered herself onto one knee with a small black ring box in hand.

Claire then faced her while singing, unaware that her visibly nervous partner was looking up at her, waiting for her to look down and notice the ring.

When the unsuspecting woman finally saw it, her voice caught mid-verse. She gasped in shock, staring wide-eyed at Khai.

Nearby, a pet owner walking her dog stopped to watch, urging Claire with a smile: 'Yes, just say yes, please.'

The woman's curious black dog even wandered into the frame as the pair froze in place.

After a brief pause, a tearful Claire said ‘Yes,' prompting cheers and applause from strangers who had gathered to witness the proposal.

Khai then slipped the diamond ring onto her fiancee's finger before the pair embraced tightly.

The touched walker standing nearby said: 'Congratulations to you both. Have a wonderful life together.'

Claire said: 'I just released the biggest ‘yes' of my life. Khai had been keeping this secret for two months before she proposed, ever since she bought that ring.

'It was raining so badly that day while we were walking along the Long Walk in Windsor Castle. The weather was wild, and everything was muddy and wet, but there she was, still trying to find the perfect spot.

'I thought we were just doing our usual photoshoot, so I posed and played along like the normal me. I didn't see it coming. Suddenly, she was down on one knee, holding the ring, and everything just paused. My heart skipped a beat and my mind went blank. I was caught off guard and cried.'