Peter Reith, former Liberal MP, defence and workplace relations minister dies aged 72 after Alzheimer's battle

The former member for the Victorian seat of Flinders was 72.

Mr Reith was known as a workplace relations minister during the infamous union busting "waterfront dispute". He was also deputy Liberal leader and a one-time Liberal leadership aspirant. In 2001, he held the defence portfolio and for a much longer period, from 1996 to 2000, he was leader of the house.

Opposition Leader Peter Dutton has led the tributes, describing Mr Reith as a "stalwart of the Liberal Party", a "formidable politician and great Australian".

"Peter's political legacy is extensive," Mr Dutton said in a statement.

"He will be remembered most, however, for his fearlessness in the face of extreme union intimidation - especially by freeing up the waterfront to ensure Australia had a more productive, forward-looking economy.

"He was an architect of pivotal workplace reform which put the interests of employers and employees first."

Mr Reith was a key architect of the Howard government's industrial relations push to change rights and conditions. During the waterfront dispute of 1997-98, he backed the ultimately unsuccessful but provocative attempt to use Dubai-trained armed forces personnel instead of union wharfies on Australian wharves.

He supported the company Patrick Corporation when balaclava-clad guards with dogs removed the wharfies. Mr Reith's foil, former national secretary of the Maritime Union of Australia John Coombes died last year.

Former Howard government colleague Kevin Andrews tweeted, "I am saddened to learn of the death of Peter Reith - a wonderful Australian, an effective minister and parliamentarian, and a committed Liberal. May he Rest In Peace."

Liberal frontbencher Dan Tehan posted, "Vale the Hon. Peter Reith, AM. Thank you for your sound advice and friendship. You will be missed. Heartfelt sympathies to your family."

Former Victorian Liberal premier Jeff Kennett also paid tribute.

"Very sad to hear of Peter Reith's death. Too young at 72, but fond memories of a long association with Peter when he first stood for federal Parliament. Always an absolute gentleman. Best to Kerrie and family," he wrote.

His family said in a statement that he had died peacefully on Tuesday afternoon, "following a brave battle with Alzheimer's disease".

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As defence minister, Mr Reith was one of the ministers at the centre of the "Children Overboard Affair", in which there were highly charged and ultimately false government claims during the 2001 election campaign that asylum seekers had thrown children overboard to secure asylum. Mr Reith doggedly refused to correct the record.

Over 17 years in Parliament, Mr Reith served under Liberal leaders Malcolm Fraser, Andrew Peacock, John Hewson, Alexander Downer and John Howard. He was deputy Liberal leader from April 1990 to March 1993.

"He was loyal to each leader as he was to his party, whether in government or opposition," Mr Dutton said.

With the House sitting this week, and the Albanese government seeking to pass its own industrial relations reforms, it is expected parliamentarians will mark Mr Reith's legacy in Canberra.

Mr Reith leaves behind wife Kerrie and four sons Paul, Simon, David and Robert.