You stand condemned: Bernardi to Dastyari

The new Senate has got off to a fiery start with outspoken Liberal backbencher Cory Bernardi slamming Labor's Sam Dastyari for allowing a Chinese donor to pay his debts.

Senator Dastyari has come under fire for having the donor foot the bill after he exceeded his travel allowance.

The senator had reported the payment on his pecuniary interest register last year but took up Senator Bernardi's invitation to explain himself to the Senate on Wednesday.

Senator Dastyari admitted to parliament he should have paid the $1670.82 bill himself.

He has now donated the amount to charity.

But Senator Bernardi said his explanation was "wholly inadequate", insisting Senator Dastyari was hiding behind the fact he had fulfilled the technical requirements by declaring the payment.

"He hasn't detailed how it came to pass that a company with strong links to a foreign country has paid his personal responsibilities and obligations to the Commonwealth," he said.

"The intent and the integrity and the question marks that now hover over Senator Dastyari's head are the things that he needs to explain."

He said leader of the opposition in the Senate Penny Wong should "hang her head in shame" because both she and Senator Dastyari stood condemned.

Senator Bernardi was later asked to withdraw after asking Senator Wong who paid her mortgage.

"I pay my mortgage and don't be grubby," she said.