The NDP will have until March 31 to pay back nearly $3 million for its use of satellite offices, CTV News has learned.

Sources tell CTV News that the 68 NDP MPs have been ordered repayment by the end of the month.

Last month, the Board of Internal Economy (BOIE), a secretive parliamentary committee responsible for overseeing parliamentary spending, ordered the 68 NDP MPs to repay a total of $2.75 million used to staff their party's satellite offices in Montreal and Quebec City.

The committee is asking the MPs to personally repay the money. It is not clear how the repayments will be handled if the NDP MPs don't make them by March 31.

But according to the BOIE bylaws, the board has the authority to request reimbursement from MPs. Section 20 says that after 90 days or more of owing, the House can take "additional means" to collect funds, while Section 21 allows the board to bring a civil action in court.

Some NDP MPs owe around $1,000, while others face six-figure bills. For instance, Montreal MPs Alexandre Boulerice and Isabelle Morin will be asked to repay $120,000 and $170,000 respectively, while Leader Tom Mulcair and party whip Nycole Turmel owe more than $600,000 combined.

Last week, NDP lawyer Julius Grey asked Justice Minister Peter MacKay to refer the matter to the Supreme Court of Canada to advise whether the BOIE ruling is subject to judicial review.