ClubsACT chief executive Jeff House is furious at the MP's surprise demand that the trial be covered by legislation.

''Andrew Wilkie is playing a very dangerous game by formally linking the legislation and the trial,'' Mr House told The Canberra Times yesterday.

''In linking the two he is jeopardising both because if the amendments pertaining to the trial aren't acceptable to us, then there will be no trial and conversely if he is not happy with the legislation, there will be no legislation.

''At best he has significantly delayed everything and at worse put both the legislation and the trial at risk.''

The trial in the ACT of mandatory pre-commitment technology would force gamblers to set betting limits before they are able to use poker machines.

Independent Nick Xenophon, who was elected to the Senate on an anti-gambling ticket, said he did not believe the federal government would uphold its commitment to hold a trial of the measures to combat excessive gambling.

He said he had advice from a constitutional lawyer that it would not be unconstitutional to enshrine the trial in legislation.

The government was forced to pull its proposed legislation from Parliament on Thursday after it failed to get Mr Wilkie's support.

Julia Gillard had broken her promise to Mr Wilkie to legislate by May for mandatory pre-commitment technology, in return for his support of the minority Labor government.

After responding then by saying the Prime Minister did not have a backbone, Mr Wilkie has recently returned to negotiations over the issue, with Community Services Minister Jenny Macklin.

He will agree to the trial in the ACT as long as amendments ensure that all new poker machines are pre-commitment ready.

''It was important to me that these different aspects of the trial be in fact legislated,'' he said yesterday.

''We've now agreed that the key aspects of the trial will be included in the bill.''

He is insisting that the bill clarify that new machines across the country must be capable of going to mandatory pre-commitment ''at the flick of a switch''.

''She [Ms Macklin] had six weeks to stew on it and see if I will blink, but I will not blink, this is critical and if need be I will not support the bill,'' he said. Mr House said significant progress towards the trial had been made in his negotiations with officials from Ms Macklin's department.

''The [federal] government and ClubsACT have achieved more in the last two months than Andrew Wilkie has achieved in the last two years,'' he said. ''The net effect of his latest intervention is, at best, to delay reform and, at worst, to risk reform altogether. There may not be a great deal of point in continuing the negotiations until we know the outcome of the legislation because of the amendments from Mr Wilkie.

''The trial is not a legislative creature, it will come about by virtue of the negotiations between ClubsACT and the Commonwealth Government.'' The Commonwealth had reiterated that it had no power to impose a trial. ''Not withstanding the capability of gaming machines, it would be thoroughly irresponsible and impractical and ineffective to simply tell more than 6000 venues across the country to flick a switch, as it were, you just can't do that.''