Liberal MPs accused the Conservatives Friday of trying to obliterate Liberals from Canada's history, capping off a week of intense partisan sniping between Liberals and Conservatives.

At the end of the week, Liberals accused the Conservatives of deliberately hiding a display honouring Lester Pearson and the Nobel Peace Prize he won in 1957.

"I have no doubt in my mind that they would try to eradicate everything that has been good by the Liberal party and by great Liberals in this country from the history books if they could," said Todd Russell, a Liberal MP for the riding of Labrador. "Fortunately right now, they can't, but it just again speaks to the nature of this particular Conservative government."

The Pearson display, in the Department of Foreign Affairs building in Ottawa, had indeed been covered up by a backdrop and curtains set up for a press conference held by political leaders from Canada, the United States and Mexico during some end-of-week meetings held in Ottawa.

But CTV News has learned that the Pearson display was routinely hidden by backdrops set up for the press conferences of Liberal ministers during the governments of Paul Martin and Jean Chretien.

That fact, though, did not deter Liberals from attacking the Conservatives.

"For somebody to think that you've got to put a shroud over it or build a wall to hide it to keep it out of view from American government officials, that is just pathetic and I think those American government officials will think it's pathetic too," Ralph Goodale, the Liberal Government House Leader, said outside the House of Commons.

"Such action is a disgrace and an embarrassment. This attempt to hide the past just highlights the Conservative Party's abandonment of Canada's peacekeeping role," Liberal MP Maria Minna said during Question Period in the House of Commons.

A Conservative MP, Deepak Obhrai, rejected the charges as "absolute nonsense."

On Friday, at a press conference held by Foreign Affairs Minister Peter MacKay, U.S. Secretary of State Condoleezza Rice and their Mexican counterpart Patricia Espinoza, the Pearson display was indeed blocked from view by a large blue backdrop.

But several department officials as well as contractors hired to produce press conference events at the Department of Foreign Affairs building said in interviews with CTV News that the Pearson display was routinely hidden by backdrops for press conferences conducted by Liberal ministers.

Indeed, in October, 2005, former Liberal Foreign Affairs Minister Pierre Pettigrew held a press conference with Rice in the very same spot MacKay did Friday with a nearly identical setup. The Pearson display was hidden then by a backdrop set up behind Pettigrew.

The Pearson statue and medal are alarmed and wired in place, making it difficult and costly to move them. In fact, contractors say the display has been moved only once. When Liberal Prime Minister Paul Martin hosted U.S. President George Bush in 2004 and held a press conference in the same spot, contractors moved the display to the front of the stage area so it would be visible during the event.

The incident comes at the end of a week in which Liberals shouted down Prime Minister Stephen Harper during Question Period. The Liberals accused Harper of trying to read a newspaper article into the Commons' record that smeared one of their own MPs. The Conservatives spent the week attacking the Liberals for refusing to extend some controversial provisions of Canada's Anti-Terrorism Act.

MPs from other parties said the bickering between Liberals and Conservatives reached a fever pitch.

"It was a bad week. I think if the Canadian people had been able to watch the full goings-on, I think they would have been very discouraged and distressed," said Jack Layton, leader of the NDP.

"The kinds of partial half-truth accusations flying back and forth, the yelling, the shouting, even the speaker had to take the right of a party that was raising a ruckus away. So it is time to get back to recognize that we need some decorum, that everyone in that House deserves respect because Canadians sent them there."