|IAAF World Championships on the BBC|
|Venue: Bird's Nest Stadium, Beijing Dates: 22-30 August|
|Coverage: Live on BBC TV, Red Button, Radio 5 live, online, mobiles, tablets and app.|
Olympic long jump champion Greg Rutherford claims not having a union jack on Great Britain's vest "erodes the very reason we are competing".
In a statement he elaborated on his criticism of the British Athletics logo appearing on the World Championships vest instead of the union jack.
He first queried the vest on Thursday in a tweet, saying it "isn't right".
Rutherford, 28, believes his views are widely supported, "from retired legends of our sport to upcoming juniors".
Rutherford insists the union jack flag on his vest has always been a motivation for his best performances.
His statement added: "The flag is a crucial symbol of why we are competing; not for fame, not for money, not for an administrative body, but for Great Britain.
"We go out on a world stage to represent this amazing union, and this is what drives us to achieve our very best.
"Without our national flag worn proud on our bodies during competition, we diminish the very nature of who we are representing and what makes sport great."
Rutherford says the flag on his vest during London 2012 helped inspire his gold medal performance.
He recalled: "It actually took up almost the entirety of the vest - a clear statement of the garment's purpose and I can wholeheartedly say that my proudest moment in sport was standing at the top of the podium, hearing the national anthem, seeing the Union Jack flag being raised, wearing the GB kit which in its design included our national flag."
British Athletics is the brand under which UK Athletics markets the sport.
In a statement issued on Thursday, it said the union jack "remains an integral part" of the kit and that the inclusion of the British Athletics brand is to "help create a strong team identity" similar to that enjoyed by Team GB at London 2012.
British triple jumper Nathan Douglas has urged a change to the vest's design.
He told BBC Radio 5 Live: "What we want to do is go out and represent our country and compete with the union flag on our kit - that's what we've always dreamed of.
"When we go out there and win a medal, we want to drape the union flag around our shoulders. It's no different with the kit.
"A lot of the world really love our flag. It's a great identity for us. We are going out there to compete for our country, not a company or an organisation."
The World Championships in Beijing start on 22 August and Britain are sending a 63-strong team captained by European 400m champion Martyn Rooney.