Embattled Labor Party senator Sam Dastyari appears to have broken federal and state Labor Party rules on political donations by allowing Chinese donors to make payments on his behalf for travel and legal bills.

The NSW Labor Senator also pulled out of a University of Queensland lecture he was scheduled to deliver on Wednesday evening as pressure mounted for him to quit. His appearance was cancelled without explanation, but young Liberals had been planning a protest at the event.

The revelations about possible Labor rule breaches - disputed by the NSW branch - ramped up pressure on the powerbroker senator to step aside, or for Labor leader Bill Shorten to reverse course and sack him.

They could could also prompt Labor's powerful national executive body to examine Senator Dastyari's actions.