A Paris push to rid the city of the thousands of ‘love locks’ weighing down its bridges is being thwarted by tourists’ relentless romance.

For years, visiting couples have hung brass padlocks on the iron grills lining the city’s bridges to symbolise their undying love: they write their names on the locks, then toss the key into the Seine below.

About 700,000 locks are added every few months and Paris officials say they are damaging the bridges and threatening safety because of the added weight.

In a bid to stamp out the practice, officials last week began installing thick plastic panels on the Pont des Arts, the pedestrian bridge linking the Louvre to the Left Bank, depriving lovers of the grillwork needed to attach their locks.

By Wednesday, two new plastic panels were seen, with more than a dozen iron grills covered by plywood in preparation for more.

However the experiment is not working. Tourists continued to affix locks to the remaining, already-overloaded, grills – and none had heard of the anti-lock campaign.

Even the plywood has been covered in romantic graffiti.

One couple from New Zealand said they had a lock specially engraved at home to commemorate their 30-year wedding anniversary.

“I really wanted to include Paris (in our trip) to do the lock thing,” said the woman, known as Joe.

City officials say grill panels can be covered with locks weighing nearly 500 kilos.In June, part of the railing collapsed due to the weight of the locks, forcing the bridge’s temporary closure for repairs.

Authorities also say keys thrown into the Seine pollute the water.

In trying to balancing safety and cultural heritage with the demands of tourism, city hall began a social media push last month called ‘Love without Locks’.

“Our bridges are more fragile than your love,” proclaims www.paris.fr/lovewithoutlocks.

Lovers are invited to post a selfie of themselves on the bridges or at other romantic Paris spots through Twitter or Instagram with the hashtag #lovewithoutlocks.

Still, a selfie lacks the romantic allure of a brass lock, especially since Paris love locks are now known far and wide. “We really wanted to do this when we were in Paris,” said one couple, who had written Esther y Javi on a lock they affixed to the Pont de l’Archeveche.

“You hear about this all the way back in Spain.”