Australian Prime Minister, John Howard, has brushed off questions about why his Government was happy for the US to charge Australian citizen David Hicks under retrospective legislation, but was against passing such laws so he could be tried in Australia.

Mr Howard said: "What the Americans do is up to the Americans... We believe the arrangements for the military commission meet the reasonable requirements of Australian law."

US military authorities announced at the weekend they had drafted new charges against Mr Hicks, who has been held for more than five years at Guantanamo Bay without trial. They include providing material support for terrorism and attempted murder in violation of the law.

The charges will be laid once approved by a convening authority - which has yet to be appointed - under a law that was passed in the US only last year.

The Howard Government has refused to bring Mr Hicks back to Australia for trial on the basis it was unwilling to try him under retrospective laws - something it would need to do as there were no applicable terrorism laws in place at the time of his alleged offences.

Mr Howard repeated this yesterday, saying "we do not believe the passage of retrospective criminal law in this country is appropriate".

But he said "once somebody goes overseas they lose the protection of Australian law".

Pressed on the appropriateness of the US using retrospective laws to try Mr Hicks, Mr Howard then said: "I don't equate what the US is doing with the passage of a retrospective criminal law in Australia. I don't accept the analogy."

The shadow attorney-general, Kelvin Thomson, challenged the Government to clarify its position on the application of retrospective legislation to Mr Hicks.

Mr Thomson said the Attorney-General, Philip Ruddock, had said he was averse to a retrospective law being passed in Australia to deal with Mr Hicks but at the weekend had welcomed the US move to charge him when one of the proposed charges, material support for terrorism, "was not an offence until the US Military Commissions Act of 2006 made it one".

"Will Mr Ruddock raise with the US its plan to try David Hicks under a retrospective law?" Mr Thomson said. "Or does he believe it is not OK to charge David Hicks in Australia under retrospective Australian law, but it is OK to charge David Hicks under retrospective American law at Guantanamo Bay?"

The issue of retrospective laws is among a number of concerns about Mr Hicks that will be raised by a group of Coalition backbenchers when the party room meets tomorrow for the resumption of Parliament.

Although Mr Hicks now looks likely to be charged, some backbenchers are concerned about the sort of trial he is scheduled to face.

"It's a question of human rights. He's an Australian citizen and he's entitled to those rights," one Coalition MP said yesterday. "Basic human rights principles have been ignored."

The Labor leader, Kevin Rudd, said: "I have never been a defender of Mr Hicks; I have been a consistent defender of Mr Hicks's legal rights and his human rights, and this US military commission is itself a travesty of justice."

A NATIONAL television advertising campaign showing a close-up of David Hicks as a freckled, nine-year-old schoolboy will try to humanise the Guantanamo Bay detainee after the weekend announcement of serious charges against him.

The GetUp support group has prepared the advertisements, voiced over in Melbourne on Friday by Hicks' father Terry, to emphasise Hicks' status as an Australian citizen and ask for him to be brought home.

"This is my son, David," Terry Hicks says. "He's been missing for five years, held at Guantanamo Bay. Without trial."

As a camera slowly pans in on the photo, Hicks says he believes the Guantanamo trials were created to guarantee convictions.

"I love my son," he adds. "But I've always said if he's done wrong he should have to face the consequences."

Saying he only ever wanted a fair trial for David, Terry Hicks ends by saying, "Please, let's bring David home".

The ads are due to go to air from mid-week in a national campaign costing tens of thousands of dollars, money raised by supporters of David Hicks through the GetUp campaign. The ads will run at all times of the day, including prime time, and will also be on radio.

GetUp director Brett Solomon said the campaign was being run in direct response to the announcement of the charges against Hicks and sought to remind the Australian people of Hicks' humanity. "This has become a political football, not a question of justice, and we want to bring his humanity back to the story," Mr Solomon said.

Mr Solomon said the announcement of the likely charges against Hicks did not alter the view of Hicks' supporters that he should be brought back to Australia to be dealt with in a recognised judicial system.

"If the Prime Minister thinks this is the end of the 'Bring David Hicks Home' campaign it's not, it's just the beginning," he added.

He said the campaign was being paid for directly by donations made by Hicks' supporters.

GetUp will also move a travelling Hicks billboard from Adelaide to Canberra this week to coincide with the reopening of Federal Parliament.

The ad campaign, narrated by Terry Hicks:

"This is my son, David. He’s been missing for five years – held in Guantanamo Bay. Without trial. He was born in Australia, grew up in Australia, is an Australian citizen. I love my son, but I’ve always said if he’s done wrong he should have to face the consequences. I only ever wanted David to be given a fair trial, but I’m sure that the Guantanamo trials have been created by politicians to do one thing: guarantee convictions. Please, let’s bring David home. Thank you – I’m Terry Hicks."