Well this is an interesting conundrum. Legally, it appears the Liberals are on good footing in having used the Green Shift terminology for their plan's launch and branding. The Toronto company, also known as "Green Shift," is seeking to put a stop to the use of the name, however, despite the fact that the trademark they've sought has not been granted. Searches are turning up a litany of uses of the term, including a "Green Shift Corporation" in New York. So what's to be done? I'm in favour of the O'Malley wisdom here...the preferable option here would be to work out some kind of solution with this company. Having said that, the owner of the company is insisting on an absolute ceasing and desisting on the Liberals' part. Which, legally, the company may not be entitled to obtain. So, it may be that there's no solution to be worked out, it's just carry on as is.
I'd point out as well, that the Liberals have already made it clear that the two green shift sites and entities are not related and are directing traffic to the company site. Here's the first thing you see on google when you look up "green shift" in respect of the Liberal site. It's all about the company, not the Liberal site:
There's a bit of goodwill to build on, perhaps?
(h/t Red Tory)