The opposition parties wasted no time in question period Tuesday as they pounced on the events surrounding an RCMP raid on Conservative Party headquarters in Ottawa.

The raid came after Elections Canada asked the Mounties to execute a search warrant.

At least two police officers entered the office, and later rolled a cart full of boxes and bags out of the 12th floor downtown Ottawa office and into a mail room.

Then elections official Andre Thouin left the office with a box of documents.

The Liberals claim the raid is part of an independent probe by Elections Canada into alleged Conservative Party irregularities into national election spending. The Tories have suggested that Tuesday's search of their offices is related to a lawsuit launched by the Tories, who are challenging an Elections Canada ruling.

The government agency had refused to reimburse the Tories for $1.2 million in advertising spending during the last election. Elections Canada said the Tories had surpassed their national ad allowance and refused to accept the Tory claims that local ads were not national in scope.

CTV's Ottawa Bureau Chief Robert Fife said the raid appears to be related to a plan referred to as an "in-and-out" scheme. Under such a plan, money would allegedly be sent to candidates across the country -- up to $50,000 in cash -- which they would then pay back to the central office, claiming it was payment for advertising.

The local ads they have been accused of paying for were allegedly almost identical to national ads, with the addition of a tagline naming local candidates. Critics say the plan allegedly would allow the party to overspend at the national level.

Questions of legality

Fife noted earlier Tuesday that "there are lots of questions about whether this may be illegal or not illegal."

While party officials maintain they didn't break any campaign spending rules, Elections Canada disagrees.

Elections Canada launched a probe a year ago into $1.2 million worth of Tory ads. After the last election, Chief Electoral Officer Marc Mayrand had refused to reimburse 67 Conservative candidates for part of the advertising money when they claimed it as local expenses.

The Tories claim they did nothing wrong.

"It's always been the case that all political parties transfer money in some ridings to the central party," Government House Leader Peter Van Loan told CTV's Mike Duffy Live.

He said it was "absurd" to argue that candidates cannot refer to national issues or their leader in local advertising.

But opposition parties are accusing the Tories of outright fraud.

"For Mr. Van Loan to say 'every party does it,' in fact, that's not true. Elections Canada found that only in the case of the Conservatives," said Liberal House Leader Ralph Goodale.

Goodale dismissed claims the RCMP raid was related to the Conservatives' civil suit about local election spending.

"It's that national aspect that the elections commissioner is investigating. It's a quasi-criminal kind of investigation that does involve the RCMP and does involve search warrants."

John Enright, a spokesperson for Elections Canada told The Canadian Press the RCMP's assistance was requested by elections commissioner William Corbett to help carry out a search warrant.

Enright wouldn't say why the warrant had been issued.

RCMP Cpl. Jean Hainey said the RCMP was only assisting.

"It is not an RCMP investigation. We're there to assist, but that's it."

Tories under fire

During question period on Tuesday, the Tories said they have done nothing wrong. Prime Minister Stephen Harper noted that the Tories have launched court action against the Elections Canada over the issue and they were set to question elections officials on Wednesday.

The Tories say they have a disagreement about the government agency's interpretation of election law. Harper said the Tories have been forthcoming in handing over all relevant documents.

"It's unclear why Elections Canada undertook this action (Tuesday)," the prime minister said.

But opposition members appeared flabbergasted.

"How did it get to this -- an RCMP squad raiding the offices of the Conservative Party," asked Liberal Deputy Leader Michael Ignatieff.

"Why did (the RCMP) have to pry information from this government's clenched fist ... This is what you get when you play fast and loose with election law. This is what you get when you stonewall Elections Canada ... This is what you get with this prime minister. He sets the tone. Will he finally admit (that) this is about his character?"

NDP Leader Jack Layton said the Tories are suggesting that the Mounties "have gone fishing" for documents. But Layton claimed it appears instead the Conservatives have gone back on their word to provide a more transparent government than the Liberals. The NDP leader then accused the Tories of following in their predecessors' footsteps.