At 7.30pm yesterday, more than 1000 protesters switched on their phones and shone lights onto the Sydney Opera House in an attempt to wipe out the giant horse-racing advertisement being projected onto the building’s iconic sails.

At the same time in Melbourne, Victorian Premier Daniel Andrews’s Facebook account trolled the advertisement, and Sydney itself, with one smug post that said: "Look, I don't think advertising belongs on the Opera House either. But if they're going to, they may as well give Victoria a plug ..."

The Facebook post also had images of the Sydney Opera house superimposed with text and images touting Melbourne’s superiority over the harbour city.

His slogans included phrases like: “24 HR NIGHTLIFE (WITH NO LOCKOUTS)”, “24 HR TRANSPORT”, “MORE JOBS” and “LOCALLY BUILT TRAINS”.

Another image lists major sporting events in Melbourne including the F1 Grand Prix, the Australian Open and the AFL Grand Final.

Perhaps the most provocative image used by Andrews to fuel the so-called “rivalry” between the cities was the Victorian state government logo – in Labor Party red – superimposed onto the sails.

New South Wales Liberal Party Premier Gladys Berejiklian has been heavily criticised for allowing the Racing NSW advertisements to be projected onto the Sydney icon.