Of course its political!

What's the point of being in power if you can't use government agencies to target and harass your enemies?
It's a time-honoured political tradition around the world, and now it's come to Canada.

The NDP is calling for an independent probe into the Canada Revenue Agency's targeting of some Canadian charities for their political activities.
In a letter Wednesday to Revenue Minister Kerry-Lynne Findlay, the party says the alleged misuse of tax agency audits against political opponents of the government is muzzling charities and draining them financially.
...A Canadian Press investigation reported that the tax agency has stepped up its probes of charities for their political activities, well beyond a first wave of audits of key environment groups that challenge the government's energy policies.
International aid groups, anti-poverty organizations and human-rights agencies have also been swept up in the net, with some 52 political-activity audits now in progress.
An initial budget of $8 million set out in the 2012 budget has grown to $13 million, and political-activity audits are being made a permanent part of the Canada Revenue Agency's work.
Asked for comment on the NDP letter Wednesday, Findlay's office provided a week-old statement that itself repeated the minister's talking points in the House of Commons: "CRA audits occur at arm's length from the government and are conducted free of any political interference."
Some charities report that the audits are driving up their legal bills, to more than $100,000 in one case, as they consult lawyers to represent their case to the tax agency. Some audits have dragged on for more than two years with no end in sight.

Mere coincidence? Ha, ha, it is to laugh.
We all know that there's a long-standing conservative meme that environmental organizations, anti-poverty groups, social justice charities, international aid NGOs and welfare agencies are all just secret fronts for traitorous evil leftists -- being reality-based, of course these organizations have a liberal bias.
The Harper Cons already know how much of their own support at the polls is coming from conservative-aligned groups like the ethical oil, right-to-lifers and evangelical churches.  So it would also be an article of faith that the leftie organizations must be secretly abusing the nation's charity rules to shill for the Libs and the NDP and the Greens.
The Harper Cons would never believe that their opponents would play by the rules, because they don't themselves, as Carol Goar notes in the Toronto Star:

Many of the “political activity” audits launched by CRA since 2012 were triggered by complaints from Ethical Oil, a lobby group with strong ties to the Harper government and the petroleum sector. This is a departure for CRA. Unlike the random audits it has always conducted — approximately 900 a year — the new ones are susceptible to external direction, compromising the fairness and professionalism in which the tax department has always taken pride.

It wouldn't surprise me if it turns out the whole strategy of targeting left-wing charities and dragging out audits was just another sleazy political tactic from the Harper PMO.