Frankie Dettori has threatened to quit the Jockeys' Association unless the minimum riding weight is raised.
Dettori's lowest weight is 8st 6lb
The Irish authorities raised their minimum weight last year after a study highlighted problems of dehydration and inadequate body fat and bone density.
"I am concerned about myself and my colleagues now but I am also looking to the future and the young apprentices," Dettori told BBC Radio Five Live.
"If we senior jockeys don't do anything about it, it will be a big problem."
The current minimum riding weight in Britain is 7st 12lb although many races do require riders to carry a higher weight.
"The British Horseracing Board and the Jockey Club decided to raise the weights of some of the races but they didn't do it right throughout the sport," said Dettori.
"I am 5ft 4 inches and weigh 9st 9lb but I have to sometimes go down to 8st 6lb.
"I have been doing this for 18 years so I know how to handle myself but I am looking out for other people in the future."
Dettori, who is the most famous Flat rider in Britain, said he was prepared to act if no action is taken.
The Italian has threatened to quit the Jockeys' Association, which is funded by riders' earnings.
"I have decided to make a stand and if it doesn't get sorted, I am willing to resign as it is not helping me, my colleagues or the young apprentices coming through the ranks who have a good future ahead," said Dettori.
John Blake, chief executive of the Jockeys' Association, said that the weights issue was "an emotive and on-going subject".
He added: "I haven't had a chance to speak to Frankie yet but I hope - without being too forward - that he won't quit.
"We are not shutting up shop, far from it, and Frankie does have some very good views on the subject and I support him on that.
"This is an issue the Association takes very, very seriously and we've been discussing and negotiating on the matter since September.
"The jockeys' viewpoint is a very broad church. Some jockeys are quite happy doing the lower weights and then there are those that struggle a little with their weight.
"The Association is responsible for every jockey riding so we need to take everybody into consideration."