Sydney FC are up in arms about the proposed rebranding of Melbourne Heart in line with club owners Manchester City, protesting that there is only room for A-League team playing in sky blue.

Twice champions Sydney have played in sky blue, the state colour of New South Wales, for 10 years, while Heart have played in red and white stripes since they entered the league in 2010.

Manchester City led the consortium which bought Heart in January and are expected to change the club’s name after registering the business name Melbourne City FC with the local authorities.

The English Premier League club last year established New York City Football Club, who will play in sky blue when they enter the Major League Soccer competition next year, and Melbourne are expected to follow suit.

“In a competition with only 10 teams, the idea of two teams wearing sky blue is nonsensical especially when sky blue is so closely associated with NSW,” Sydney FC Chairman Scott Barlow said.

“I believe it’s critical to the integrity of the A-League that clubs have identities that are also in representation of where they come from.”

Football Federation Australia would have to approve the re-branding of Melbourne Heart, and Sydney FC are not the only interested party opposed to the colour change.

Banners at recent Heart matches have urged the new owners of the four-year-old club to “Keep Melbourne Red and White”.

Heart, who had Malta striker Michael Mifsud in their ranks this season, finished bottom of the A-League after a 3-2 home defeat to Western Sydney Wanderers in their final game of the regular season last weekend, which attracted 10,000 fans for Harry Kewell’s last match.