The shadow home secretary said police were right to look again at whether former minister Denis MacShane's abuse of expenses broke the law.
Yvette Cooper said the case should be re-examined in the light of "very severe condemnation" by parliament's sleaze watchdog.
The comments came after the Commons authorities insisted that damning letters from Mr MacShane to the standards commissioner could not be used against him in court.
Senior officials say they are protected by parliamentary privilege because they were collected during proceedings of the House.
More top news
ITV News Political Editor Robert Peston has travelled to Yorkshire to find out the views of voters in an area which voted to leave the EU.
Heavy rain - mostly across Wales - will clear eastwards throughout the day tomorrow
A former coach and kit man at Scottish football clubs has been charged with sexual activity with a child.