RUGBY union has been urged to follow the lead of rugby league in the fight to reduce the effect of repeated head knocks.

The Rugby Football League has extended return-to-play protocols which mean players who fail concussion tests in matches or at training must now wait at least 11 days before playing again.

That is up from seven days while in elite rugby union the minimum requirement remains at six.

Progressive Rugby, a lobby group formed to lead the bid to tackle the issue of serious head and brain injury, is hoping the move will prompt officials of the 15-man code to take similar action.

Professor Bill Ribbans, of behalf of Progressive Rugby, said: "We applaud the RFL for addressing the game's graduated return-to-play protocol (GRTP) and sending a strong message that playing a contact sport within a week of suffering a concussion is no longer acceptable.

"To World Rugby, we re-iterate our call for an initial amendment to the GRTP so that players are stood down for a minimum period of 12 days and hope that the RFL's decision may provide the impetus to do so."

Former England forward James Haskell, a prominent member of the group, added on social media: "Well done Rugby league! Turns out you can make instant changes. Come on @WorldRugby.

"Times a ticking. If you want to put me in charge I will show you how to change it all in a few days."