The club's chief executive David Temme has written to the Bluebirds' 9,000 season ticket holders and members urging them to support the scheme at Leckwith by lobbying councillors, AMs, MPs and Cardiff council.
In a New Year message to fans, Mr Temme said: "We need everyone to understand that this is a football stadium for Cardiff and for Wales, and that it is a stadium for all the people and one that will take Wales and Welsh football forward to new heights.
"Everyone who supports the new stadium project has a right to have their views known and recorded and this goes for all ages.
"Some fans are concerned that those councillors who are against the project will say that the views of the fans are biased in favour of the scheme - good, and so they should be.
"Why is it wrong for people to stand up for what they believe in, anyway?"
Urging fans to write to the politicians, Mr Temme said: "We do need each and every one who is for the scheme to now help the club and stand by their club, their team and allow us the opportunity to move forward into the upper divisions of the football world.
"It doesn't need to be a literary work of art - or a masterpiece of prose - just something from the heart in support of the project.
"It will make a difference." A spokesman for Cardiff council said it expected the planning application, which also includes proposals for retailing, a replacement athletics stadium and a hotel, to be considered by councillors in late spring or early summer.
WHY CARDIFF CITY SAY THEY SHOULD HAVE A NEW STADIUM
* Ninian Park is an outdated stadium.
* Between 1,200 and 1,500 new jobs would be created.
* A new stadium with Cardiff City in the First Division would generate more than £20m a year, rising to £50m in the Premier League.
* It would be safer, with segregation between rival fans.
* The stadium will cost taxpayers nothing.
* Cardiff would have a new athletics stadium.
* Badly-needed new homes could be built at Ninian Park.
* The scheme involves the treatment of a former rubbish tip.
* Cardiff City would have its own car parking in addition to space for the retail areas. Congestion and access to the area on match days would be reduced.
* Cardiff deserves a new stadium - something which many clubs in England have had already.
Here is a list of all the Cardiff County Counsillors. By clicking on their profile you can select an option to email them.