Prime Minister Turnbull said he had not been "bought by anyone" after revealing he donated more than a million dollars to the Liberal Party's war chest in the lead up to the July 2 election.
Labor has accused the multi-millionaire of buying himself an election, however, on Thursday Mr Turnbull attacked Opposition Leader Bill Shorten's credibility.
"I'm not a wholly-owned subsidiary of the CFMEU [Construction, Forestry, Mining and Energy Union] like Bill Shorten. I'm my own man, and Bill Shorten hates that," Mr Turnbull said.
"I can't be bought. I don't belong to anybody. I'm my own man, I put my own money backing my values and my party."
On Wednesday evening the Prime Minister admitted to making a donation of $1.75 million to the Liberal Party in the lead up to the July 2 election, after spending six months avoiding the question.
His announcement came just hours after calling for an overhaul of political donations in a speech to the National Press Club in Canberra.
"That was the contribution I made. It has been talked about and speculated about so there it is," Mr Turnbull told the ABC on Wednesday evening.
Mr Turnbull said he put his money into the campaign to ensure "we didn't have a Labor government".
"I put my money where my mouth is. I stand up for my values, with the money that I've made, the money I've paid tax on."
Deputy Labor Leader Tanya Plibersek has accused Mr Turnbull of buying himself an election, and has called for the political disclosure threshold to be reduced from $13,200 to $1,000.
"I think it's pretty extraordinary that he's tried to keep it secret for so long... he should have been upfront from the beginning." Ms Plibersek said.
Labor's Finance Spokesman Jim Chalmers went further, saying he heavily relied on the financial backing.
"If Malcolm Turnbull didn't have $1.75 million to splash about he wouldn't be the leader of the Liberal Party and he wouldn't be the prime minister," he said.
"No wonder Malcolm Turnbull was so desperate to keep his secret – he basically bought himself an election."
Foreign Minister Julie Bishop said she welcomed the fact that the Prime Minister was prepared to "invest" his own money in causes such as the Liberal Party.
"Bill Shorten should be answering questions about the millions of dollars that the unions funnel into the Labor Party in return for what?" Bishop asked.
Treasurer Scott Morrison has defended the Prime minister's contribution and praised Mr Turnbull and wife Lucy's generosity.
"That's a grubby political smear from a grubby political hack in a party of hacks led by Bill Shorten," he said.
Crossbench senator Nick Xenophon said he believed there should be real-time disclosure of donations, to overcome a lack of transparency.
He argued both major parties were as bad as each other regarding political donations.
"People in glass houses shouldn't throw stones and this is one hell of a big glass house," Mr Xenophon said.
