Peter Costello, treasurer for the entire 11 years of the Howard government and architect of the GST, says a report pointing out the necessity of tax reform isn't enough.

What's needed is a policy and a political plan, he said at the National Archives of Australia launch of cabinet documents of the coalition government for 1998 and 1999.

In that period, the coalition embarked on a program of major tax reform, introducing the GST, negotiating new financial arrangements with states and territories and educating the public and businesses on the new arrangements.

The period of that process included a federal election, which the coalition won with a reduced majority.

Then the government had to negotiate with Senate minor parties to get its 29 pieces of legislation passed.

"If you are going to do tax reform you need a policy, obviously. We had a policy. That's what we went to the election on. Secondly you need a political plan to implement it," Mr Costello said.

"You don't just put out a report and say 'Have a look at that' and 'I'm stunned that it wasn't implemented.'

"This is hard. If you think balancing a budget has a degree of difficulty - it's seven out of 10. Try major tax reform - it's about 17 out of 10."

Mr Costello said a timetable was needed.

He said the political plan was to explain how the current system was broken, what was necessary to fix it and then ask everyone to bear the cost.

It was also essential to make sure the vulnerable were compensated, to show that tax reform can produce wider benefits and to neutralise potential opponents.

Mr Costello said the coalition government knew who would oppose the new tax as they had seen it in the 1993 election campaign when then opposition leader John Hewson stood on a platform of tax reform and lost.

Obviously Labor would object.

"We knew that charities were a problem, we knew that churches were a problem. That's why they all got such good taxation treatment," he said.

"We knew the states were a problem. That's why they got the revenue guarantee."

Mr Costello said the proponents of tax reform needed to develop a mandate.

By winning the 1998 election which was fought almost wholly on the GST, the government gained such a mandate, although that didn't end the opposition from Labor and minor parties.

"Prepare the administration and implementation. Work like buggery to make sure it gets there and get ready before the next election to defend it," Mr Costello said.

"These are hard things to do and it is only because they were done back in 1998 and 1999 we have had 20 much better years than would otherwise have been the case. There are a lot of lessons there."

Short of major reform, Mr Costello said current governments needed to keep working on income tax rates as bracket creep continually made those rates less and less competitive.

"There's still a lot that can be done in the simplification," he said.

"Complexity is growing all the time in tax and there is a real economic benefit in simplicity in taxation. Compliance is a huge cost."

Australian Associated Press