ROME Swimsuits will almost certainly have to be made from textiles from January and men are poised to return to trunks, swimming's governing body FINA said on Friday.
Controversy over performance-enhancing polyurethane bodysuits, not regarded as a textile, has overshadowed the Rome world championships, which start on Sunday.
"The material is to be textile," FINA executive director Cornel Marculescu told a heated and tense news conference.
"In general it is going to be short trunks. But let us finish the rules."
The details of the new rules will be thrashed out after another meeting on July 28 when the exact measurements for men's and women's outfits for 2010 will be ratified.
Full bodysuits will remain for these championships, where they are expected to cause a raft of world records.
FINA only agreed recently to allow all-polyurethane suits, which critics say trap air and aid performance, but the chastened governing body is now ready to reverse that decision after heavy pressure.
Polyurethane is a polymer which is not regarded as a textile as it is impermeable. Common textiles are formed by weaving together fibers such as cotton and are permeable.
A return to textiles would mean the world records recently broken in polyurethane suits and those expected to be smashed in Rome would be almost impossible to be bettered in traditional costumes in the short term.
All records will stand, however.
"There is no way we are going to reconsider the existing world records," Marculescu added.
Michael Phelps, winner of eight gold medals at last year's Beijing Olympics, was happy with the proposed new rules.
"I like it. I think it is going to be good," he said.
British swimming's performance director Michael Scott backed the idea of putting an asterisk by world records that were achieved in polyurethane suits to distinguish them from records before and after their introduction.
With new rules coming in only after the worlds, the saga will rage on given most swimmers have freedom to choose what suit they use next week.
The British swimmers, who have a contract with Speedo but are allowed to race in rival suits, were banned from being asked directly about the row in their pre-meet news conference.
Britain's double Olympic champion Rebecca Adlington said earlier in the week the suits were like technological doping.
Like Phelps, Beijing's 400 and 800 meter freestyle gold medalist has decided to wear Speedo's LZR suit which was the first of the new generation of costumes but has now been usurped by the likes of Jaked's all-polyurethane suit.
She refused to be drawn on whether she could be competitive.
"You just have to watch out for everybody. I do feel stronger than I did in Beijing. But as I'm older, I do need recovery," the 20-year-old said.
(additional reporting by Paul Virgo)
(Editing by Justin Palmer)