BIKIES would face jail for being members of outlawed clubs under legislation the Government plans to put to Parliament within six months.

But there is understood to be tension between the Minister for Police, Tony Kelly, and the Attorney-General, John Hatzistergos, over how tough the legislation should be.

Motorcycle clubs are fighting the proposals and have instructed barristers across the country to mount legal challenges against any attempts by the states to follow South Australia's lead and have bikie gangs be proscribed as criminal groups.

The South Australian laws are untested as no groups have yet been proscribed, although the Finks have been targeted.

The NSW Premier, Nathan Rees, said he hoped similar legislation would be introduced by the end of June.

But questions about how far the powers should go have emerged in cabinet. Mr Hatzistergos and his department are understood to be concerned at some elements of the legislation. Sources said there was resistance to some of the tougher restrictions requested by police.

The South Australian Premier, Mike Rann, yesterday requested that "criminal bikie laws" be put on the national agenda at the next premiers' conference.

An Adelaide solicitor, Craig Caldicott, who represents the Finks Motorcycle Club, said he was briefing several barristers to challenge any government's attempts to ban the organisation.

He had been instructed to fight the laws in the High Court if necessary.

Motorcyclists, including members of outlawed clubs, have formed a political party, Free Australia, to fight the laws in South Australia and potentially across the country if more states introduce them. A spokesman, Paul Kuhn, said the violence at Sydney Airport on Sunday was disgusting and would make it harder to campaign against the laws.

Under South Australia's Serious and Organised Crime (Control) Act 2008, outlawing a club must follow secret reports from the police commissioner to the attorney-general. The act does not use the words motorcycle gangs or even clubs.