How is BQ veto of a Lib-NDP coalition possible?

This is another talking point I keep running into in discussions with Conservative-minded people: the BQ would have an effective veto over the coalition. This is usually followed by Bloq-bashing. Check out The Galloping Beaver.

How could the BQ veto anything with only 49 votes of 308?

Here's the current mix:

• 143 Conservatives
  
• 77 Liberals
  
• 49 BQ
  
• 37 NDP
  
• 2 Independent

The veto argument only works if the Conservatives consistently vote against the government too. If they vote with the government or abstain, the coalition outnumbers the BQ (and you could neglect the 2 independents).

I believe this exposes the deeply partisan thinking in this argument. Why wouldn't the Conservatives absent enough MPs to allow such a vote to pass? If they could simply vote with the coalition to prevent a "BQ veto", why wouldn't they? Or more to the point, why would they vote with the BQ?

If the Conservatives are voting against a motion, wouldn't they welcome help from the BQ to defeat it? After all, if the BQ votes with the coalition the motion would pass.

Only the partisan assumption that the Conservatives would vote against the Lib-NDP coalition consistently without regard to the matter of the vote holds up the argument of a BQ veto. Of course everything depends on the subject matter of the vote, but that nevers appears in those Conservative-minded talking points.