OTTAWA — In highly-anticipated testimony to Parliament on Thursday Canadian Prime Minister Justin Trudeau denied any conflict of interest in awarding a lucrative government contract to an organisation that had previously paid members of his family.

Trudeau spoke in his own defence before the Finance Commission for 90 minutes, an exceptional move for a Canadian head of government, as he tries to ward off an escalating scandal.

"There was never any direction by or attempt to influence from me or my staff that the public service recommend WE Charity," he said referring to the group central to the probe.

WE Charity has said it paid Trudeau's mother and brother nearly CAN$300,000 for speaking engagements in recent years.

Trudeau's wife was paid CAN$1,500 for an event in 2012, before her husband became the leader of the Liberal Party.

Trudeau apologised for the affair on July 13, saying he made a "mistake" in not recusing himself from discussions about awarding a student scholarship fund government contract to WE Charity that was initially estimated at CAN$990 million (US$662 million).

Canada's youth minister has said the programme's final value actually came out to about CAN$500 million, local media reported.

The charity has given up the programme, but the controversy remains. The organization could have already received more than CAN$40 million, according to reports.

'Nobody believes you'

The opposition Conservative Party has also accused WE Charity of reimbursing Trudeau relatives another CAN$212,000 in travel expenses.

The prime minister acknowledges he was aware of his relatives' activities with the charity, but that he was not abreast of any remuneration, including travel expenses.

"Nobody believes you when you say you don't know how much money your family has got from the group," Conservative spokesman Pierre Poilievre said.

"How much money total have your brother, mother and spouse received from this organisation, how much?"

Both main opposition parties have called on Trudeau, who heads a minority government, to resign.

The Conservatives are basing their numbers on testimony given by WE Charity's co-founders Craig and Marc Kielburger to the Finance Commission on Tuesday.

"We were not chosen for this work by public servants because of our relationship with politicians," the brothers insisted during their four-hour appearance.

Finance Minister Bill Morneau, who has also found himself ensnared in the matter as a second subject of the ethics investigation, said last week that he had paid back more than CAN$41,000 in travel expenses to the charity.

Morneau also apologised for his involvement in discussions about disbursing contracts to WE Charity, as one of his children is employed by the organisation.

Morneau's reimbursement check was meant to cover expenses incurred by the charity over two humanitarian trips he and his family took in 2017.

The scandal has damaged Trudeau in public opinion polls, but his party is still positioned well for an early election, according to the average of four polls cited by Canadian public broadcaster CBC.

More than half of the country -- 53 per cent -- said they now have a lower opinion of Trudeau than they did a month ago, according to one such poll.

The prime minister has run afoul of the ethics commissioner on two previous occasions since 2017 for conflict of interest violations. — AFP