A worker repaints the bumper of a tram at a depot in Hong Kong on Aug 25. [Photo/Agencies]

A controversial new proposal to take Hong Kong's beloved trams off the streets has sparked a wave of anger from residents who fear losing the city's past.

Known as "ding-dings" for the sound of their bells, trams have served the northern coastline of the city's main island for more than 110 years and still carry around 200,000 passengers a day.

As development changes the face of the city, sweeping away many of its historic landmarks, trams have survived in the face of growing competition from buses and the modern metro system.

But a recent proposal to scrap part of the network has renewed fears that this unique piece of heritage is also under threat.

Thousands signed petitions against the suggestion that the tram service should be removed from the main financial district of Central.

The proposal was put forward to the government's official town planning body by consultant Sit Kwok-keung, a former planner, who argues that it is too slow, blocks traffic and is unnecessary as the metro system expands.

The retired civil servant said putting the idea forward for debate is his "right and responsibility".

"The tramway takes up a significant portion of the road. Its efficiency is rather low. ... I am trying to make Hong Kong transportation more efficient," he said.

The planning body will discuss the proposal in October, but the Hong Kong government has sought to reassure the traveling public by saying it had no plans to remove the trams.

But unease remains.

"Public sentiment is strongly against this idea," activist Kwong Sum-yin, who is leading the "Save The Trams" campaign, said.

"Trams are forward-looking as a form of zero-emission transport when the world is talking about sustainability."

Kwong's group, the Clean Air Network, is instead proposing a car-free zone in Central to ease congestion and make way for more trams to run.

"We are losing our history. That's why Hong Kong people don't want to see one more thing go," Kwong said.

With 163 tramcars, Hong Kong's tram network is the world's largest fleet of double-deck tramcars still in operation, charging a flat rate of just HK$2.30 (30 US cents) for adults to ride the 120-stop system.

Hong Kong Tramways managing director Emmanuel Vivant said the network is a "key part of what makes Hong Kong a great city" and argues that trams are not to blame for traffic congestion.

Many residents of the city of seven million are increasingly focused on preserving its past, as economic development takes a toll on Hong Kong's transport heritage.

But despite public support for the tram system, Sit says it is time for a review.

"Efficiency is the most important thing to every person," he said.

He added that if his proposal for Central went through, he would advocate for the complete removal of trams throughout the city.

Sit argues that trams should instead be turned into "mobile museums".

"Why should some outdated transport mode remain here?" he said.