CANBERRA, Australia – Australia’s wealthy prime minister has revealed that he donated 1.75 million Australian dollars ($1.3 million) to his cash-strapped party’s re-election campaign last year, prompting his opponents to accuse him of buying the election victory.

Prime Minister Malcom Turnbull, Australia’s richest lawmaker with a fortune estimated to exceed AU$200 million, had refused for months to say how much he had contributed to his Liberal Party-led conservative coalition scraping back into power at elections on July 2.

But he confirmed the figure late Wednesday, despite being legally entitled to conceal it for another year.

“I’ve always been prepared to put my money where my mouth is,” Turnbull told Australian Broadcasting Corp.

“I put my money into ensuring that we didn’t have a Labor government,” he added, referring to the centre-left Labor Party opposition.

Secrecy surrounding the size of Turnbull’s donation has added to calls for Australia to reform its political donation laws to ensure more transparency.

Labour’s finance spokesman Jim Chalmers on Thursday accused Turnbull of buying the election in which the coalition clung to power with the barest majority of 76 seats in the 150-seat House of Representatives.

“It stinks. Malcolm Turnbull had to buy his way out of trouble,” Chalmers said.

“If Malcolm Turnbull didn’t have AU$1.75 million to splash about, he wouldn’t be the leader of the Liberal Party and he wouldn’t be the prime minister,” Chalmers added.

Treasurer Scott Morrison described Chalmers’s comments as “a grubby political smear from grubby political hack.”

Morrison, a senior Liberal Party member, accused opposition leader Bill Shorten of doing the bidding of the labour union movement, which donates to the Labor Party.

Under Australian electoral law, political donations exceeding AU$13,200 made in the last fiscal year had to be published on Wednesday along with the names of the donors.

Turnbull avoided his disclosure by promising the money to his Liberal Party during the election campaign but not making the donation until the current fiscal year. The current fiscal year started on July 1 — the day before the election. Party officials had been desperately lobbying donors for more money to maintain their campaign in the final weeks.

Calls for Turnbull to admit the donation intensified when he was absent from the donors’ list published on Wednesday. His absence highlighted one of the tactics donors can use to avoid or delay disclosure.

The former merchant banker’s wealth is seen as a political liability, with his opponents accusing him of being out of touch with the financial pressures facing most ordinary Australians.

The 62-year-old self-made multi-millionaire has been dubbed “The Silvertail,” a pejorative term for someone with wealth and privilege, and “Mr. Harbourside Mansion.” Cartoonists depict him wearing a top hat.

A parliamentary committee is currently considering changes to Australian electoral laws to increase transparency.

Labour wants the disclosure threshold reduced to AU$1,000 while minor party lawmakers suggest donations should be disclosed when they are made.