About 48,000 unionized urban Canada Post workers began strike action June 2 at 11:59 p.m. ET, with a rolling strike that started in Winnipeg and then moved to other cities including Hamilton, Montreal, Edmonton, Calgary, Victoria, Quebec City and Kitchener, Ont., among others. Following 12 days of rotating strikes, Canada Post locked out the workers on June 14.

Here are handy facts about the job action:

Why a lockout?

Canada Post said it had no choice when faced with an "accelerating" decline in volumes and revenue, combined with an "inability to deliver mail on a timely and safe basis." Canada Post claims the rotating strikes have caused losses approaching $100 million.

The Canadian Union of Postal Workers called the move "irresponsible" and "counterproductive."

Will any mail be delivered?

Canada Post has ceased nearly all mail delivery nationwide, with the exception of monthly social assistance payments such as government pension cheques, veterans' cheques and child benefit cheques. Those cheques would all be delivered on June 20 by letter carriers in uniform who had agreed in advance to be on the job throughout a work stoppage for this reason. Rural carriers are still on the job so those in rural areas can expect to receive mail for another couple of days.

Can I still mail a letter?

Mail boxes are in the process of being sealed. If you should find one that is not yet sealed, don't drop mail into it as it will not be delivered as there is no way of picking it up.

All corporate mail outlets are closed. Retails mail outlets will remain open, though will not accept mail or parcels for delivery. Electronic options, such as e-post, will still be available.

Why Winnipeg  first?

The Canadian Union of Postal Workers says Winnipeg was chosen because it was the first city to undergo Canada Post's modernization program. The union says that program has led to a deterioration in public service and serious health and safety problems relating to new equipment and work methods.

What does the union want?

A key issue for the union, which represents close to 50,000 letter carriers and other workers, is Canada Post's modernization program. The union said it involves new methods such as requiring letter carriers, who walk on average 15 kilometres a day, sometimes in bad weather, to carry multiple bundles on their routes instead of just one. Inside workers stand for eight-hour shifts at new machines that are twice as fast at processing the mail. Another major issue is Canada Post's demand to eliminate the sick leave plan for all employees and replace it with what the union calls an inferior short-term disability plan. The union is asking for a four-year contract with wage increases of 3.3 per cent in the first year and 2.75 per cent in years two and three. The union opposes an 18 per cent wage cut for new hires. Pensions are also an issue.

What has Canada Post offered?

Canada Post called the union's offer "out of touch" with the challenges currently facing the Crown corporation, which includes a core letter-mail business that has fallen by more than 17 per cent per address since 2006, and a current pension deficit of $3.2 billion. Canada Post has tabled an offer that includes a defined benefit pension plan for both new and existing employees, seven weeks vacation after 28 years of service and job security. Canada Post has made what it said were a number of compromises on issues, including sick days and the wage for new hires. It also took its intention to hire more part-time workers off the table.

Will the government intervene?

On June 23, MPs voted to limit debate on a motion that will allow for Bill C-6 to be pushed through the House of Commons in one sitting instead of going through the normal number of readings and committee stages. Debate on that motion will continue throughout the day but will be brought to a vote — and passed with the Conservative majority — at 8 p.m. ET. Then the debate on the bill itself will get underway and it could go around-the-clock. The House of Commons won't rise for their summer break until the legislation is passed. Both the NDP and the Liberals are opposed to it. Prime Minister Stephen Harper defended the government's action and the bill's measures, which include wage increases that are lower than the ones offered to the union by Canada Post at the negotiating table.

Has this happened before?

The last time Canada Post workers went on strike was in 1997. The government of the day forced an end to the strike with legislation after about two weeks.

What do postal workers make?

The average starting wage for postal workers is $23 an hour.