Ms Lawder submitted her travel proposal on April 2. On April 3, in a surprise decision, the tribunal abolished the travel allowance. It brought forward its decision after news of a $36,000 trip to Europe and South Korea by Liberal Assembly members looking at prostitution laws.

The tribunal wanted to make sure there was no further call on the budget, hoping to make savings to offset a proposed rise in members' pay. Tribunal chairwoman Anne Cahill Lambert said on Tuesday she had not known of Ms Lawder's proposal, lodged the day before.

Caught in the crossfire, Ms Lawder was forced to cancel her trip. She was to take her adviser with her, following the precedent set up by Giulia Jones, who leaves for her prostitution study trip on April 21, and is the first Assembly member to use the study tour allowance to pay for a staff member to travel overseas.

Speaker Vicki Dunne would not release details of proposed study tours caught up in the scrapping of the budget, forcing this newspaper to obtain the documents relating to Ms Lawder's trip under freedom of information laws.

Ms Lawder is the Liberals spokeswoman on housing and a former chief executive of Homelessness Australia. She is travelling to Tanzania next month to attend a seminar of the Commonwealth Parliamentary Association (a trip to be funded separately) and had planned to tack the housing study on to that trip.

She was to spend five days in London visiting housing groups, the Housing Minister and the London School of Economics to look at models of public housing, an issue, she said, in which she had a keen interest.

Ms Lawder said Canberra had a housing affordability crisis. Canberra's homelessness rate was the second-highest of any jurisdiction in the country, and it was impossible to deal with homelessness without affordable housing. While Canberra had a much higher percentage than other states of homeless people being looked after in crisis accommodation and homeless shelters, they could not get out into affordable housing. There were 12,000 public housing properties in the city, and 2000 people on the wait list.

In Britain, public housing had looked to be in ''terminal decline'' but had been turned around. It now had a useful model popular with tenants, the government and financiers, she said. It was disappointing her study tour could not go ahead, but attending in person was ''not the be-all and end-all'' and she would do the work from Canberra.

''Housing is such an important part of people's lives. It's almost impossible to maintain employment and education if you don't have a home, stable secure housing as a base, and to me it seemed like a great opportunity to investigate some policies that were turning around public housing in the UK to see if there were any policy levers that we could us here in the ACT.''

The ACT government is preparing to redevelop the 381 ''ABC'' public housing units in Cooyong Street. Just 10 per cent of the new development will be set aside for public housing. The government is considering the future of 472 occupied public housing units in Northbourne Avenue, which is being redeveloped for the introduction of a light rail line from Gungahlin.

The prostitution tour escaped the ban on study travel. Mrs Jones leaves with her adviser on April 21 to join Mrs Dunne for their examination of prostitution laws which criminalise paying for sex.