Radical rule changes, including the introduction of sin-bins and video referees, could be implemented in time for next year's Six Nations Championship if the International Rugby Board agrees to a series of proposals put forward yesterday after a conference in Sydney on the game's future.

The board is not due to discuss the raft of reforms until March but has been urged to convene a special meeting within the next four weeks.

The Sydney think-tank, which was attended by 60 of the world's leading administrators and coaches including Clive Woodward, Graham Henry and Rod Macqueen, was organised by the IRB to address concerns that the game had become too defensive and unappealing to spectators and sponsors. The proposed changes include the introduction of sin-bins and video referees at international and professional club levels; a use-it-or-lose-it law applying to scrums; and changes to the tackle, maul and lineout laws.

The board's game development manager, Lee Smith, was uncertain whether the laws would be changed in time for the Six Nations. "There are procedures in place to ensure that decisions are not taken precipitately," he said yesterday, "but they are not cast in tablets of stone."

Players and teams who consistently infringe to stop their opponents gaining possession will be sinbinned, although the drastic sanctions introduced in Wales - where a team is warned after three offences, a player sent to the sin-bin for a side's fourth indiscretion and a red card issued to the fifth culprit - are unlikely to be adopted.

Former England captain Phil de Glanville faces a lengthy lay-off following confirmation that he suffered a fractured cheekbone in Bath's defeat at Wasps on Sunday.